Practice Free SAA-C03 AWS Certified Solutions Architect - Associate (SAA-C03) Exam Questions Answers With Explanation

Amazon Aurora Serverless is a fully managed, MySQL-compatible database that automatically scales based on demand and provides high availability. Combining this with EC2 Auto Scaling and an Application Load Balancer achieves both application and database high availability and scalability.

Reference Extract:

" Aurora Serverless automatically starts up, shuts down, and scales capacity based on your application ' s needs, providing a cost-effective, highly available database solution. "

Source: AWS Certified Solutions Architect – Official Study Guide, Aurora Serverless and Scaling section.

A. EventBridge rule:Triggers an event whenever there is a change in CloudFront distribution, ensuring real-time monitoring.

B. ALB with WAF:Focuses on application-level security, not CloudFront logging.

C. Lambda + SNS:Provides notifications upon detection of changes in logging configuration.

D. GuardDuty:Monitors anomalies but does not specifically address CloudFront logging changes.

E. Private API + WAF:Irrelevant to CloudFront logging changes.

Amazon CloudFront is a content delivery network (CDN) service that distributes content with low latency and high transfer speeds. Placing CloudFront in front of the S3 bucket ensures globalusers download content from the nearest edge location, reducing latency significantly.

Option A is the best answer because it introduces both decoupling and horizontal scalability with minimal infrastructure management. API Gateway provides a managed front door for the microservices, Lambda provides serverless compute that scales with request volume, and SQS provides durable buffering between transactional stages such as order creation and payment processing. AWS recommends queue-based decoupling when producers and consumers operate at different speeds or when spikes must be absorbed without losing work. The EKS and EC2 alternatives add significantly more operational burden, and caching does not solve the core workflow-scaling issue. Therefore, a serverless microservices architecture using API Gateway, Lambda, and SQS is the best fit.

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DynamoDB Accelerator (DAX) is a fully managed, in-memory cache for DynamoDB that delivers up to a 10x performance improvement—even at millions of requests per second. DAX requires minimal changes to existing applications and offloads the read workload from DynamoDB during report generation.

Reference Extract:

" DAX provides in-memory acceleration for DynamoDB tables, reducing response times from milliseconds to microseconds with minimal application changes. "

Source: AWS Certified Solutions Architect – Official Study Guide, DynamoDB and Performance section.

Amazon RDS for MySQL Reserved Instances provide significant savings over on-demand pricing when you plan to run the database for long periods. This is the most cost-effective option for non-production, long-running managed MySQL workloads.

Reference Extract:

" Reserved Instances provide a significant discount compared to On-Demand pricing and are recommended for steady-state workloads that run for an extended period. "

Source: AWS Certified Solutions Architect – Official Study Guide, RDS Cost Optimization section.

The problem is contention between two very different workloads that currently share one target group and one scaling boundary. The correct fix is to useALB path-based routingso /reports and /generateToken go toseparate target groups, each backed by its own Auto Scaling group. AWS ALB listener rules support path-based routing, which lets different paths scale independently and isolates the latency-sensitive /generateToken path from the CPU-heavy /reports workload. Making the instances larger does not remove the contention boundary, and CloudFront is not the right answer for two dynamic uncached paths. Therefore, splitting the paths into independent target groups and scaling units is the best architecture.

Using SQS as a buffer between S3 and the Lambda function ensures durability and allows for retries in case of processing failures. Messages in the queue can be retried by Lambda, and failed processing can be directed to a dead-letter queue for further inspection. This guarantees reliable and scalable message-driven processing.

The least operational overhead approach is to use AWS Directory Service with AWS Managed Microsoft AD and establish a trust relationship with the existing on-premises Microsoft Active Directory. This pattern lets employees continue using their existing corporate credentials while AWS operates the directory infrastructure (patching, monitoring, availability, and domain controller management), reducing the burden compared to building and maintaining custom federation components. With a trust in place, identities and group memberships from the on-premises directory can be used for authentication and authorization workflows in AWS.

To provide role-based access to AWS resources and the AWS Management Console, users should assume IAM roles that grant permissions based on job function. IAM roles with appropriate trust policies enable temporary credentials and least-privilege access without creating long-lived IAM users for every employee. This aligns with AWS best practices of centralized identity management and using roles for access control.

Option B is not a standard direct integration pattern: IAM does not “LDAP bind” directly to on-premises AD for console access. Option C can work (custom identity broker + STS) but increases operational overhead because the company must build, secure, operate, and maintain the broker, including availability, updates, and incident response. Option D is not the typical solution for employee console federation from AD; Amazon Cognito is primarily aimed at customer identity and application sign-in, not as the primary mechanism for workforce console access to AWS accounts.

Therefore, A provides the required federation with the smallest operational footprint while supporting role-based access control.

AWS Secrets Manager is the best fit because it is built specifically to store, manage, and rotate secrets such as database credentials. AWS documentation states that Secrets Manager supports automatic rotation for supported secret types and reduces the need for custom credential-rotation code. KMS encrypts keys and data but is not itself a secret-rotation store. Parameter Store can hold secure strings, but Secrets Manager is the AWS service purpose-built for secret lifecycle management and scheduled rotation. Because the question asks for the least development effort, using Secrets Manager with automatic rotation is the most direct and operationally efficient solution.

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Amazon Kinesis Data Streams is designed for low-latency ingestion of streaming data. Combined with Amazon Managed Service for Apache Flink, telemetry can be processed and aggregated in near real time. Processed metrics can be sent to Amazon CloudWatch, which natively supports creating dashboards, metrics visualization, and alarms. Firehose (B) is primarily for batch ingestion and delivery, not real-time analytics. EMR with Athena (C) introduces more complexity and is better for large-scale offline analytics. DynamoDB Streams (D) is not a fit because telemetry data is not stored in DynamoDB. Therefore, option A provides the most suitable and real-time analytics pipeline for telemetry data.

The company needs a cloud-based storage solution for frequently accessed data with low latency, while retaining their current on-premises infrastructure for some data storage. AWS Storage Gateway ' sVolume Gateway with cached volumesis the most appropriate solution for this scenario.

AWS Storage Gateway - Volume Gateway (Cached Volumes):

Volume Gateway with cached volumesallows you to store frequently accessed data in the AWS Cloud while keeping the most recently accessed data cached locally on-premises. This ensures low-latency access to active data while providing scalability for the rest of the data in the cloud.

The cached volume option stores the primary data in Amazon S3 but caches frequently accessed data locally, ensuring fast access. This configuration is well-suited for applications that require fast access to frequently used data but can tolerate cloud-based storage for the rest.

Since the company is facing limited on-premises storage, cached volumes provide an ideal solution, as they reduce the need for additional on-premises storage infrastructure.

Why Not the Other Options?:

Option A (S3 File Gateway): S3 File Gateway provides a file-based interface (SMB/NFS) for storing data directly in S3. While it is great for file storage, the company’s need for block-level storage with iSCSI targets makes Volume Gateway a better fit.

Option C (Volume Gateway - Stored Volumes): Stored volumes keep all the data on-premises and asynchronously back up to AWS. This would not address the company ' s storage limitations since they would still need substantial on-premises storage.

Option D (Tape Gateway): Tape Gateway is designed for archiving and backup, not for frequently accessed low-latency data.

AWS References:

AWS Storage Gateway - Volume Gateway

Amazon API Gatewayprovides a scalable and reusable solution for interacting with DynamoDB without requiring direct access by developers. By setting up a REST API with a POST methodthat integrates with DynamoDB ' sPutItemaction, developers can submit data (such as user ratings) to the DynamoDB table through API Gateway, without having to directly interact with the database. This solution is serverless and minimizes operational overhead.

Option A: Using ALB with Lambda adds complexity and is less efficient for this use case.

Option B: While using Lambda is possible, API Gateway provides a more scalable, reusable interface.

Option C: SQS with Lambda introduces unnecessary components for a simple put operation.

AWS References:

Amazon API Gateway with DynamoDB

Aurora global database is specifically designed for cross-Region disaster recovery and low-latency global reads.

It provides:

Physical storage-level replication between Regions, typically with lag of under 1 second, easily satisfying RPO 1 minute.

Fast cross-Region failover capabilities, often within minutes or less, which meets the RTO 5 minutes requirement.

You configure the primary Region as the writer cluster and additional Regions (such as us-west-1) as secondary clusters with reader endpoints. In a disaster, you promote the secondary to be the new writer.

Why others are not correct:

A: Standard cross-Region read replicas for Aurora PostgreSQL do not provide automatic multi-Region failover with the same guarantees as Aurora global database and may not meet strict RTO/RPO requirements.

C: Logical replication and custom EventBridge failover is complex, error-prone, and higher overhead compared to the managed global database feature.

D: Restoring from snapshots plus cross-Region replication is too slow to meet RTO 5 minutes and certainly cannot maintain RPO 1 minute.

The best AWS-native design isAmazon Kinesis Data Streamsfor real-time ingestion andAmazon OpenSearch Servicefor near-real-time search and analytics. AWS describes OpenSearch Service as a managed search and analytics engine for real-time application monitoring and similar use cases, and AWS also provides architectures for delivering real-time data from Kinesis into OpenSearch. QuickSight is then appropriate for dashboards and visualizations. The other answers either introduce more operational overhead or use services that are not the best fit for real-time search workloads. For an on-premises search application moving to AWS, Kinesis plus OpenSearch is the most natural managed solution.

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The requirement is for immediate processing of uploaded videos and prompt notification to users. According to AWS best practices for event-driven architectures, using S3 event notifications to trigger a Lambda function upon an object creation (upload) is the optimal solution for real-time processing. Lambda can process the file as soon as it is uploaded, ensuring low latency. Once processing is complete, Lambda can save the processed file back to S3 and use Amazon SNS to notify the user.

This approach uses managed services with minimal operational overhead, is scalable, and ensures event-driven processing with instant user feedback. AWS Amplify primarily facilitates application development and hosting but does not natively provide direct push notification support for this backend workflow; instead, SNS is designed for such notification scenarios.

Reference Extract from AWS Documentation / Study Guide:

" Amazon S3 can publish events to AWS Lambda when objects are created. AWS Lambda runs code in response to events and can interact with other AWS services. Amazon SNS is a flexible, fully managed pub/sub messaging and mobile notifications service for coordinating the delivery of messages to subscribing endpoints and clients. "

Source: AWS Certified Solutions Architect – Official Study Guide, Event-driven Architectures section; AWS Lambda Developer Guide (S3 triggers); Amazon SNS User Guide.

Comprehensive and Detailed Step-by-Step Explanation:

The company needsautomatic monitoringandnotificationsforsecurity violationsin Amazon Redshift clusters.

Option A:?

Create an Amazon EventBridge rule that uses the Redshift clusters as the source. Create an AWS Lambda function to evaluate the Redshift cluster security configuration. Configure the Lambda function to notify the company of any violations of the security policies. Add the Lambda function as a target of the EventBridge rule.

EventBridgecan trigger actionsbased on events.

However, itdoes not track changesin Redshift security configurations.

Why not?AWS Configis bettersuited forcompliance monitoring.

The performance issue occurs because reporting queries compete with production traffic on the same primary database instance. The best-practice AWS solution is to offload read-heavy workloads to a separate database endpoint.

Option C adds an Amazon RDS read replica, which asynchronously replicates data from the primary instance. By redirecting reporting queries to the replica endpoint, the primary database can focus on transactional workloads, significantly improving application performance and customer experience.

Read replicas are specifically designed for this use case: scaling read capacity and isolating reporting or analytics queries. This solution requires minimal changes to the reporting job (endpoint update only) and avoids overprovisioning the primary database.

Option A (RDS Proxy) improves connection management but does not reduce query load or isolate reporting traffic. Option B is invalid because Multi-AZ does not scale reads and is not configurable across three AZs for a single instance. Option D increases instance size but does not address the underlying contention between workloads and increases cost unnecessarily.

Therefore, C is the most efficient and scalable solution to minimize reporting impact while maintaining high performance and availability.

Amazon EMR on EC2 supports “runtime roles (application-scoped IAM roles)” so each application/step assumes its own IAM role with least-privilege S3 access. You enable this via an EMR security configuration by setting “EnableApplicationScopedIAMRole = true.” The EMR core/Task nodes run under the cluster’s EC2 instance profile; therefore the instance profile must be permitted to “sts:AssumeRole” into the defined EMR runtime roles, and each runtime role must trust the instance profile (trust policy principal is the instance profile role). This design limits each job’s S3 scope via role policies and enforces per-job access segregation. Option B reverses the trust (incorrect). Option E trusts the EMR service role (not used to assume runtime roles). Option F is unrelated (encryption in transit). The correct trio is to enable application-scoped roles (A), authorize the instance profile to assume them (C), and configure the runtime roles’ trust relationship to allow that assumption (D).

The workload isstateless,parallel, and each job runs for about20 minutes, which makes Lambda a poor fit because Lambda has a maximum execution time of 15 minutes. AWS Fargate is a strong match for event-driven container workloads because it removes server management overhead, andFargate Spotlowers cost for interruption-tolerant processing. AWS also provides patterns for runningevent-driven workloads at scale with Fargate, and EventBridge can be used to trigger container tasks from S3-originated events. Compared with EKS or EC2 On-Demand, ECS on Fargate Spot is the most cost-effective managed container approach here.

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Detailed Explanation:

A. EventBridge Rule:Detects modifications to CloudFront distributions in real time and triggers the Lambda function for further action.

B. ALB + Config:Focuses on ALB security violations, not relevant for CloudFront logging changes.

C. Lambda + SNS:Provides real-time notifications about changes in logging configuration.

D. GuardDuty:Focuses on threat detection, not logging configuration changes.

E. API Gateway + WAF:Unrelated to CloudFront logging changes.

Kinesis Data Streams is the right ingestion service for real-time streaming data, and AWS Lambda is the least-operations compute option for processing and transforming records from the stream. AWS documents that Lambda can process events from stream sources such as Kinesis without infrastructure management. Storing the transformed data in DynamoDB provides durable, scalable storage for later analysis. The EC2 option introduces server management overhead. SQS is useful for queued work, but the question specifically centers on streaming data. SNS with ElastiCache is also not a durable analysis store design. Therefore, Kinesis Data Streams plus Lambda plus DynamoDB is the lowest-overhead architecture among the choices.

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The requirement has two parts: (1) continuously or regularly evaluate IAM access key age against a 90-day policy, and (2) remediate noncompliant keys by disabling and deleting them. The least operational effort generally comes from using managed compliance evaluation and lightweight serverless remediation.

AWS Config is designed to assess resource configuration compliance over time. Using an AWS Config rule to check access key age fits the governance model because Config maintains a compliance history, supports central reporting, and can evaluate keys across an account (and commonly across an organization with aggregation patterns). After detection, remediation should be automated with minimal infrastructure, and AWS Lambda is the lightest operational tool for directly calling IAM APIs (UpdateAccessKey to Inactive, then DeleteAccessKey) on a schedule.

Option C pairs these appropriately: Config performs compliance evaluation, and an EventBridge scheduled rule triggers a Lambda function to remediate keys older than 90 days. This avoids running and maintaining compute fleets or batch infrastructure. It also provides clear separation of duties: Config for detection and evidence, Lambda for corrective action.

Options A, B, and D rely on AWS Batch, which introduces additional operational overhead (compute environments, job definitions, queues, scaling, and monitoring) that is unnecessary for a simple IAM housekeeping task. Also, EventBridge by itself is not a compliance evaluation service; it can schedule a job, but it does not inherently track “key age” state or compliance posture the way Config does.

Therefore, C best meets the requirement with the least operational effort by using Config for continuous compliance visibility and a scheduled Lambda for automated key deactivation and deletion.

The correct answer isAbecause the application is alightweight data processing toolthat always completes within3 minutes, which fits well within the execution model ofAWS Lambda. Lambda is a fully managed compute service that eliminates the need to provision or manage servers, clusters, operating systems, or container hosts. Since the company is willing to make any required changes to the image, packaging the workload as aLambda container imageis the option with the least operational overhead.

Lambda is well suited for short-lived, event-driven, or on-demand processing jobs. It automatically scales, charges only for execution time, and removes nearly all infrastructure administration. Compared with container orchestration services, Lambda requires less setup, less monitoring of infrastructure, and no task or cluster capacity planning.

Option B is incorrect becauseAmazon EKS with Fargatestill requires Kubernetes management constructs and introduces more operational complexity than Lambda. Option C is simpler than EKS, butAmazon ECS with Fargatestill involves managing task definitions, services, and networking, which is more overhead than Lambda for a brief processing job. Option D is incorrect because using a custom AMI with AWS Batch introduces more compute management and is unnecessary for a very short, lightweight workload.

AWS guidance favorsserverless serviceswhen the workload is short-lived and infrastructure management should be minimized. Because this job always completes quickly and the company wants the least operational overhead,AWS Lambda with a container imageis the best solution.

Amazon RDSMulti-AZ DB cluster deploymentensures high availability by automatically replicating data across multiple Availability Zones (AZs), and it supports failover in case of a failure in one AZ. This setup also provides increased capacity for read workloads by allowing read scaling with reader instances in different AZs. This solution offers the most operational efficiency with minimal manual intervention.

Option A (DynamoDB): DynamoDB is not suitable for a relational database workload, which requires a PostgreSQL engine.

Option B (RDS with Multi-AZ): While this provides high availability, it doesn ' t offer read scaling capabilities.

Option D (Cross-Region Read Replicas): This adds complexity and is not necessary if the requirement is high availability within a single region.

AWS References:

Amazon RDS Multi-AZ DB Cluster

This workload is a strong candidate forAWS Batch with EC2 Spot Instancesbecause the jobs can tolerate interruptions and resume after restart. AWS documents that Spot Instances are a cost-saving option for interruption-tolerant workloads, and AWS Batch is built to manage batch jobs efficiently across EC2 capacity. AWS Batch guidance also notes that Spot is well suited when jobs can be retried or resumed, which matches the scenario. On-Demand Capacity Reservations do not optimize cost, and Savings Plans still cost more than Spot for an interruption-tolerant batch pattern. Therefore, AWS Batch with Spot gives the best balance of automation and lower compute cost.

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Amazon Macie is a fully managed data security and data privacy service that uses machine learning and pattern matching to discover and protect sensitive data in AWS. To scale across Regions and accounts in AWS Organizations, Macie supports delegated administration, automated sensitive data discovery, and multi-account aggregation through a centralized admin account.

The correct answer isDbecause the application peak hours occur at thesame time each day, and the performance issue happens specifically at thestart of peak hours. This indicates that the company knows in advance when additional capacity will be needed. Ascheduled scaling policyis the most appropriate solution because it allows the Auto Scaling group to increase capacitybeforedemand rises, ensuring that instances are already launched and available when users begin accessing the application.

Dynamic scaling based on CPU or memory reacts onlyafterutilization increases. Because launching EC2 instances takes time, reactive scaling can lead to delays and degraded user experience at the beginning of peak periods. That directly matches the problem described in the question, where performance is slow at the start but normalizes later once capacity catches up. Scheduled scaling solves this by making capacity available proactively.

Option A is incorrect because an Application Load Balancer distributes traffic among existing instances but does not add capacity ahead of predictable demand. Option B is incorrect because Auto Scaling does not natively scale on memory utilization unless a custom metric is configured, and even then it would still be reactive rather than proactive. Option C is also incorrect because CPU-based dynamic scaling reacts after demand increases and therefore may not prevent the startup lag during peak traffic.

AWS design guidance recommends usingscheduled scalingwhen traffic patterns are predictable and occur at known times. This approach improves application responsiveness and user experience by making sure enough EC2 capacity is available before the workload surge begins.

To build a distributed, serverless, event-driven workflow with minimal operational overhead, AWS Step Functions orchestrating AWS Lambda is the best fit. Step Functions provides a managed state machine service that coordinates multiple steps, handles retries and error handling patterns, and maintains execution state without requiring the company to run orchestration servers. Lambda provides serverless compute for each workflow task, scaling automatically with demand and eliminating server management.

Option D directly matches “performing different aspects of the workflow” because Step Functions is specifically designed to model multi-step business processes and coordinate activities across services. It also aligns with “minimize operational overhead” because both Step Functions and Lambda are managed services: there are no instances to patch, no cluster management, and scaling is handled by the platform.

Option B contradicts the serverless goal by deploying the application on EC2 instances, increasing operational overhead (capacity management, patching, scaling, and availability concerns). Option C mixes eventing with scheduling: EventBridge can route events, but invoking Lambda “on a schedule” is not the same as orchestrating a multi-step workflow with branching, waiting, retries, compensation, and state tracking. EventBridge is excellent as an event bus, but Step Functions is the purpose-built workflow orchestrator. Option A is a mismatch because AWS Glue is primarily an ETL/data integration service; while it can run jobs and triggers, it is not the general workflow orchestrator for arbitrary application steps, and using it to invoke Lambda for a broad workflow is less direct and typically less operationally clean than a Step Functions state machine.

Therefore, D is the most aligned solution for serverless, distributed workflow orchestration with low operational burden.

Amazon Neptune: Neptune is a fully managed graph database service that is optimized for storing and querying highly connected data. It supports both property graph and RDF graph models, making it suitable for applications that need to analyze relationships between data entities.

Neptune Streams: Neptune Streams captures changes to the graph and streams these changes to other AWS services. This is useful for applications that need to monitor and respond to changes in real-time, such as providing recommendations based on user interactions and relationships.

Least Operational Overhead: Using Neptune Streams directly with Amazon Neptune ensures that the solution is tightly integrated, reducing the need for additional components and minimizing operational overhead. This integration simplifies the architecture by eliminating the need for a separate service like Kinesis for change processing.

AWS recommends Auto Scaling with dynamic scaling policies to handle unpredictable workload spikes. Target tracking scaling policies automatically adjust capacity based on defined metrics such as average CPU utilization or request count per target. This approach ensures applications maintain responsiveness without overprovisioning. Scheduled scaling (options B and C) is only effective when traffic patterns are predictable, which is not the case here. Reserved Instances or Spot Instances also do not address sudden demand changes effectively. Replacing the ALB with an NLB (D) does not solve latency caused by EC2 instance capacity. Therefore, using EC2 instances in an Auto Scaling group with a target tracking scaling policy is the most effective and cost-efficient solution for unpredictable, short-lived traffic spikes.

Dead-letter queues (DLQs) with Amazon SQS allow Lambda functions to offload failed events for later inspection or retry. Using retry logic with exponential backoff ensures resilience and compliance with best practices for fault-tolerant serverless architectures. This guarantees no data is lost due to transient errors.

For near-real-time streaming workloads that are highly latency-sensitive, the network layer must provide ultra-low latency and high throughput between compute nodes. Elastic Fabric Adapter (EFA) is specifically designed to meet these requirements. EFA enables EC2 instances to communicate using a high-performance network interface that bypasses traditional TCP/IP networking, providing lower and more consistent latency. This is especially valuable for tightly coupled workloads that require fast inter-node communication.

Option B is the correct choice because EFA supports custom networking stacks and is optimized for applications such as real-time data processing, distributed computing, and high-performance workloads. EFA integrates directly with supported EC2 instance types and allows applications to take advantage of enhanced networking capabilities without requiring complex multi-VPC architectures.

Option A introduces additional network hops and latency due to VPC peering and is not suitable for ultra-low-latency workloads. Option C (spread placement groups) is designed to increase fault tolerance by placing instances on separate hardware, but it does not optimize for low-latency communication and may actually increase network distance between instances. Option D improves storage performance, not network performance, and does not affect inter-instance latency.

Therefore, B is the best solution because Elastic Fabric Adapter is the AWS-recommended approach for achieving the lowest possible network latency between EC2 instances in performance-critical streaming architectures.

AWS documentation states that Amazon Macie is the managed service designed to automatically identify and classify sensitive data stored in Amazon S3, including PII and healthcare-related identifiers.

Storing logs in Amazon S3 provides scalable, durable storage, and Amazon Athena can directly query JSON data stored in S3 using SQL.

Amazon Inspector (Option D) is for vulnerability scanning and does not identify sensitive data. DynamoDB with KMS (Option C) cannot detect sensitive information. EBS (Option B) requires custom tooling and does not support serverless SQL querying.

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This is a classic fanout pattern. AWS documentation states that Amazon SNS can fan out messages to multiple subscribers, including Amazon SQS queues. AWS also notes that using SQS with SNS gives each subscriber its own durable queue, which buffers events independently and allows consumers to process at their own pace. That directly satisfies the need for every consumer to receive each order event, to absorb bursts, and to let new consumers be added without changing the producer. A single SQS queue would distribute messages across consumers instead of delivering every event to every consumer. Direct EventBridge targets do not provide the same durable per-consumer buffering described in the question. SNS plus one SQS queue per consumer is the most flexible and resilient design.

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If the SQS visibility timeout is set shorter than the time it takes for the application to process and delete the message, the message becomes visible to other consumers and can be processed again, resulting in duplicate processing. This is a common cause of duplicate messages when using SQS.

Reference Extract from AWS Documentation / Study Guide:

" If the visibility timeout for a message is set shorter than the time it takes to process the message, the message becomes visible again and can be received and processed again, resulting in duplicate processing. "

Source: AWS Certified Solutions Architect – Official Study Guide, SQS and Messaging section.

For cost-effectiveness and high availability in Amazon EMR workloads, the best approach is to configure atransient cluster(which runs for the duration of the job and then terminates) withOn-Demand Instancesfor the primary and core nodes, andSpot Instancesfor the task nodes. Here ' s why:

Primary and core nodes on On-Demand Instances: These nodes are critical because they manage the cluster and store data on HDFS. Running them on On-Demand Instances ensures stability and that no data is lost, as Spot Instances can be interrupted.

Task nodes on Spot Instances: Task nodes handle additional processing and can be used with Spot Instances to reduce costs. Spot Instances are much cheaper but can be interrupted, which is fine for non-critical tasks as the framework can handle retries.

Atransient clusteris more cost-effective than a long-running cluster for workloads that only run for 6 hours a day. Transient clusters automatically terminate after the workload completes, saving costs by not keeping the cluster running when it ' s not needed.

Option A: A long-running cluster may result in unnecessary costs when the cluster isn ' t being used.

Option C: Running core nodes on Spot Instances risks data loss if the Spot Instances are interrupted, violating the requirement for zero data loss.

Option D: Running both core and task nodes on Spot Instances is highly risky for data-critical workloads.

AWS References:

Amazon EMR Cluster Management

Using Spot Instances in EMR

Given the large size (180 TB) of the database and the time constraint,AWS Snowball Edge Storage Optimizedis the best solution. Snowball Edge allows for the physical transfer of large datasets to AWS efficiently without relying on slow internet connections.AWS DMSandSCTcan be used to perform ongoing replication of any changes made during the migration, ensuring minimal downtime.

Option B (VPN): Using a 100 Mbps internet connection would take far too long to transfer 180 TB.

Option C (Direct Connect): Establishing a 10 Gbps Direct Connect link might not be feasible within the 2-week timeframe.

Option D (DataSync over internet): With the existing internet connection, DataSync would also take too long.

AWS References:

AWS Snowball Edge

AWS DMS

State Machine Testing with Logs:

Changing the log level to ALL enables capturing detailed request and response data. This helps verify HTTP headers, body, and responses.

Incorrect Options Analysis:

Option A and B: The TestState API is not a valid option for Step Functions.

Option C: A data flow simulator does not exist for AWS Step Functions.

When operating in disconnected or limited-connectivity environments, such as ships at sea, AWS recommends using AWS Snowball Edge devices to host local compute and storage workloads. Snowball Edge supports Amazon EC2 instances and AWS IoT Greengrass, and can run Amazon EKS Anywhere for local Kubernetes cluster deployments.

From AWS Documentation:

“You can use AWS Snowball Edge devices to run compute-intensive applications in remote or disconnected locations. Snowball Edge devices support running Amazon EC2 instances and Amazon EKS Anywhere clusters.”

(Source: AWS Snow Family – Developer Guide)

Why A is correct:

Snowball Edge provides local compute and storage even without internet connectivity.

Multiple Snowball Edge devices can be clustered together for high availability and failover.

Fully self-contained environment suitable for ships or field operations.

Why the others are incorrect:

B, C, D require network connectivity to AWS Regions or Zones (Local Zone, Outposts, Wavelength), which is not available at sea. These options cannot operate fully disconnected.

Amazon EKS Anywhere is the best fit because it is specifically designed to run Kubernetes on customer-managed infrastructure in on-premises and edge environments while simplifying cluster lifecycle management. AWS states that EKS Anywhere helps automate cluster management on your own infrastructure, which matches the requirement to keep network connectivity and underlying infrastructure on premises. By contrast, EKS on Outposts moves the platform to AWS Outposts hardware, and the self-hosted options increase operational burden because the company would still manage the Kubernetes platform itself. The key distinction here is that the company wants simpler management without giving up control of its current on-premises environment. EKS Anywhere is the AWS service built for exactly that balance.

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Amixed Auto Scaling groupwith both On-Demand and Spot Instances is the best answer because AWS documents that mixed instances groups let you launch and automatically scale a fleet of On-Demand and Spot Instances in a single Auto Scaling group to optimize cost while maintaining scale and performance. Since the workload can tolerate occasional disruptions, Spot is appropriate, but keeping some On-Demand capacity adds stability. This is a more practical architecture than moving the whole workload to Spot alone. Continuing with only On-Demand or buying Reserved Instances would not optimize cost as well for variable usage.

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Detailed Explanation:

A. RDS:Suitable for relational databases but does not provide native support for data lakes or row-level access.

B. Redshift:Primarily for analytics, not designed for large-scale data lake governance.

C. S3 + Lake Formation:Provides native support for data lakes with granular access control, including row-level permissions.

D. Glue Catalog + DataBrew:Focused on data preparation and metadata management, not row-level access control.

Instances in a private subnet cannot directly reach the internet because they do not have public IP addresses and the private subnet route table typically does not send 0.0.0.0/0 traffic to an internet gateway. However, these instances still need outbound-only internet access to download patches and updates while remaining inaccessible from the internet. The standard AWS design to achieve this is a NAT gateway deployed in a public subnet.

Option C is required because a NAT gateway must reside in a public subnet that has a route to the internet gateway. This allows the NAT gateway to forward outbound traffic from private instances to the internet and return responses, without allowing inbound connections initiated from the internet to those instances.

Option A is required because a NAT gateway uses an Elastic IP address to represent its public-facing identity on the internet. Without an Elastic IP, the NAT gateway cannot communicate with internet endpoints. The Elastic IP is associated with the NAT gateway, not with the internet gateway.

Option B is required because the private subnet needs a route for 0.0.0.0/0 (default route) that targets the NAT gateway. This ensures that outbound internet-bound traffic from the private instances is sent to the NAT gateway rather than being dropped.

Option D is incorrect because a NAT gateway in a private subnet would not have a working route to the internet gateway and would not provide internet egress. Option E is incorrect because the public subnet’s default route should point to the internet gateway, not to the NAT gateway. Option F is incorrect because you do not associate Elastic IPs with an internet gateway.

Therefore, A, B, and C correctly implement private subnet outbound internet access while keeping the instances unreachable from the internet.

The correct answer isProvisioned IOPS SSD io2 Block Express. AWS documents that io2 Block Express is recommended for I/O-intensive, latency-sensitive workloads and is designed for consistent sub-millisecond latency with very high IOPS limits. AWS also notes that many instance types can achieve up to32,000 IOPS, which matches the baseline requirement in the question. S3 is object storage and not suitable for a transactional MySQL database. EFS is a shared file system, not the preferred low-latency block storage for this database pattern. gp3 is versatile and cost-effective, but it is not the targeted choice when the requirement explicitly emphasizes sustained, low-latency 32,000 IOPS performance. (AWS Documentation)

Since the company already usesIAM Identity Center, the lowest-overhead and most consistent design is to manage access throughpermission setsassigned to groups. AWS documentation explains that permission sets are the central mechanism IAM Identity Center uses to grant least-privilege access to AWS accounts and resources. This approach fits team-based access for development, testing, and operations without having to manage individual IAM users in each account. It also aligns with AWS guidance to apply least privilege by creating restrictive permission sets instead of broad standing permissions. The other options either introduce more manual identity management or create unnecessary account complexity for the scenario described. (AWS Documentation)

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EMR runtime roles allow fine-grained permissions per job, letting each team access only the services they are authorized to use. This isolates IAM permissions per workload and avoids exposing instance-level credentials through IMDSv2. Runtime roles improve security posture in multi-tenant EMR environments.

Amazon S3 File Gateway provides a local NFS mount point, which can be used with minimal changes by the legacy application. Files are transparently uploaded to Amazon S3, allowing the web application to access them directly from S3. This is the most cost-effective and operationally simple way to bridge legacy on-premises NFS output with S3, requiring no changes to the batch process.

AWS Documentation Extract:

“With S3 File Gateway, you can provide applications a local file interface to Amazon S3. S3 File Gateway presents a file-based interface (NFS or SMB), allowing you to use S3 as your scalable, durable storage while making files available to legacy applications.”

(Source: AWS Storage Gateway documentation)

A: Outposts is far more costly and complex than needed.

B: Volume Gateway presents iSCSI block storage, not NFS.

C: Requires re-coding the legacy app to use S3 APIs, not NFS.

Amazon API Gateway supportsresource policies, which allow you to control access to your API by specifying the IP addresses or ranges that can access the API. By creating a resource policythat explicitly denies access to any IP address outside the allowed set, you can ensure that only trusted IP addresses (such as those from your internal network) can access the critical information in your API. This approach provides fine-grained access control without the need for additional infrastructure or complex configurations.

Option A (Private integration): API Gateway private integrations are for creating private APIs that are only accessible within a VPC, but this solution is about restricting access to certain IP addresses.

Option C (Private subnet and ACLs): Deploying the API in a private subnet and using network ACLs adds unnecessary complexity and isn ' t the best fit for HTTP APIs.

Option D (Security group): API Gateway doesn ' t have a security group because it isn ' t a resource inside a VPC. Instead, resource policies are the correct mechanism for controlling IP-based access.

AWS References:

Controlling Access to API Gateway with Resource Policies

AWS Budgets allows you to set custom cost and usage budgets. When actual or forecasted usage exceeds the threshold, AWS Budgets can automatically send alerts to an Amazon SNS topic. You can use AWS Cost Explorer in parallel for visual tracking of spending. This solution requires no code and has minimal operational overhead.

The key requirements are shared storage, SMB protocol support, and least administrative overhead. Amazon FSx for Windows File Server is a fully managed AWS service designed specifically to provide native SMB file shares compatible with Windows-based workloads and SMB clients.

Option D is the optimal solution because FSx for Windows File Server eliminates the need to manage operating systems, patching, backups, file server clustering, and availability. AWS handles infrastructure management, scaling, and availability, while providing high-performance file storage that integrates seamlessly with Active Directory and supports standard Windows file permissions and SMB semantics. This makes it ideal for media applications that rely on shared file access.

Option A (Storage Gateway Volume Gateway) is designed primarily for hybrid environments that extend on-premises storage into AWS, not for cloud-native shared file systems. Option B (Tape Gateway) is intended for backup and archival workflows, not active file access. Option C requires significant operational overhead, including OS maintenance, security patching, scaling, and high availability design.

Therefore, D meets all requirements with the least administrative effort while providing a scalable, secure, and highly available SMB-compatible storage solution.

Amazon EFS requires a mount target in each Availability Zone where EC2 instances access the file system. This is because each mount target provides an elastic network interface in the subnet and AZ, reducing network latency by allowing EC2 instances to communicate locally with the EFS mount target. Creating a mount target in each AZ optimizes file system access performance and availability. Instances mount the EFS file system via the mount target in their respective AZ, which provides the lowest possible latency and avoids cross-AZ traffic.

Option A, with only a single mount target in the VPC, will cause cross-AZ traffic for instances in other AZs, increasing latency and potentially incurring data transfer costs. Option B is incomplete and introduces complexity with sharing directories across instances. Option C is invalid because mount targets are per AZ and per subnet, not per instance.

Comprehensive and Detailed 250 to 300 words of Explanation (AWS documentation-based, no links):

The requirements “shard-level control” and “custom checkpointing” point directly to the Kinesis Client Library (KCL), which is designed for building consumer applications that coordinate shard processing, perform load balancing across workers, and manage checkpoints in a durable store (commonly DynamoDB) with fine-grained control. While Lambda can consume from Kinesis Data Streams, its event source mapping abstracts shard coordination and checkpoint behavior; it is not the best fit when you explicitly need custom checkpointing logic and shard-level control beyond the managed integration.

Running the existing Lambda processing logic as a long-running consumer in Amazon ECS on AWS Fargate allows the company to operate a scalable KCL-based consumer fleet without managing servers. With Fargate, AWS manages the underlying compute while the application maintains direct control over shard assignment and checkpoint timing/frequency through KCL—exactly what the requirement calls for. Latency is minimized because the consumer reads directly from Kinesis Data Streams and processes records continuously, avoiding additional buffering layers or store-and-forward patterns.

Option A adds significant latency by delivering to S3 through Firehose and then triggering processing from S3 object notifications; this is optimized for delivery and batch-style processing, not low-latency streaming with shard-level control. Options B and D introduce SQS between Kinesis and processing, which adds another hop and does not inherently provide shard-level control or KCL-style checkpointing; FIFO also limits throughput and is not intended for high-scale streaming fan-in. Increasing Lambda provisioned concurrency can reduce cold starts, but it does not solve the need for custom checkpointing at the shard level.

Therefore, C best meets shard-level control and custom checkpointing requirements with the least latency by using a direct KCL consumer on a managed compute platform (Fargate).

Amazon DocumentDB global clusters support managed cross-region failover, allowing you to promote a secondary region to become the new primary with minimal downtime. This ensures business continuity during maintenance or regional disruptions.

Reference Extract:

" Amazon DocumentDB global clusters support managed cross-Region failover, allowing you to recover quickly from regional disruptions with minimal downtime. "

Source: AWS Certified Solutions Architect – Official Study Guide, DocumentDB and Resiliency section.

To securely publish messages to an encrypted Amazon SNS topic, the following steps are required:

A. Resource policy for SNS topic:Ensures that the Lambda function is explicitly allowed to publish messages to the topic.

C. Resource policy for KMS key:Provides the necessary permissions to use the customer-managed key for encryption.

F. Lambda execution role:Grants the Lambda function the necessary IAM permissions to use the encryption key.

Other options:

Bis invalid because using SSE-KMS does not eliminate the need for resource policies.

Doverlaps with A, but specifying the ARN in the topic policy is covered by creating the resource policy.

Eis unrelated as API Gateway is not required for this setup.

AWS Documentation Reference:

Amazon SNS and KMS Permissions

According to AWS best practices, each tier’s security group must restrict inbound traffic to only the upstream trusted source. For the web tier, the Application Load Balancer must be the only entity allowed to send traffic. AWS documentation specifies: “Restrict the security groups associated with your targets to accept traffic only from the load balancer.” This confirms that the web tier security group should allow inbound HTTPS from the ALB security group (A).

For communication between the web and application tiers, AWS states: “You can specify a security group as the source or destination in a rule” and “Create rules only for the protocols and ports required by your application.” Therefore, the application tier security group must allow inbound HTTPS traffic from the web tier security group (E).

For the database tier, AWS guidance says: “Allow only the necessary ports for database communication.” Microsoft SQL Server listens on port 1433 by default, so the database tier security group must allow inbound SQL Server traffic from the application tier security group (C).

Outbound rules (options B, D, and F) are unnecessary because AWS specifies that “Security groups are stateful. Return traffic is automatically allowed.” This means once inbound rules are defined, the return path is automatically permitted without extra outbound configurations.

This combination (A, C, E) applies the principle of least privilege, ensures end-to-end secure communication across tiers, and follows AWS recommendations for ALB-to-target security group setups.

For the relational database tier, Amazon RDS Multi-AZ provides high availability with minimal manual intervention. In Multi-AZ mode, RDS maintains a synchronous standby in a different Availability Zone and provides automatic failover during certain failure scenarios. This reduces operational burden because the service handles replication, health monitoring, and failover orchestration.

For the container-based application tier, Amazon ECS with the Fargate launch type minimizes operational overhead because it removes the need to provision, patch, and scale the underlying EC2 instances that host containers. With Fargate, AWS manages the compute infrastructure, and the team focuses on task definitions, scaling policies, and application configuration. This supports a highly available, load-balanced architecture because ECS services can run tasks across multiple Availability Zones behind an Application Load Balancer, and scaling is managed via ECS Service Auto Scaling.

Option B describes read replicas, which are primarily used for scaling reads and, depending on configuration, may not provide the same automated failover characteristics as Multi-AZ for high availability. Read replicas are not a direct substitute for Multi-AZ HA. Option C (self-managed Docker cluster on EC2) is operationally heavy: you must manage node capacity, patching, cluster lifecycle, and scheduling. Option E (ECS on EC2) is a valid container platform but still requires managing EC2 instances, AMIs, and scaling/patching, which increases manual intervention compared to Fargate.

Therefore, combining RDS Multi-AZ (A) for database resilience and ECS Fargate (D) for serverless container operations meets the HA requirement with the least manual effort.

When using an SQS queue as an event source for AWS Lambda, the visibility timeout of the SQS queue plays a critical role in preventing duplicate message processing.

" If your Lambda function doesn ' t process the message and delete it from the queue within the visibility timeout period, the message becomes visible again and can be processed again by the same or another function instance. "

— AWS Lambda with SQS

In this scenario, the third-party API may take up to 60 seconds to respond. Since the Lambda function is configured with a 65-second timeout, the visibility timeout of the queue must be greater than or equal to the maximum function execution time to avoid the same message being reprocessed.

Incorrect Options:

A: Memory allocation doesn’t impact duplicate message handling.

B: Timeout is already sufficient; increasing it further does not solve the core issue.

C: Delivery delay controls initial delivery delay, not reprocessing logic.

EBS Encryption:

Default EBS Encryption: Can be enabled for new EBS volumes.

Use of AWS KMS: Specify AWS KMS keys to handle encryption and decryption of data transparently.

Amazon RDS Encryption:

RDS Encryption: Encrypts the underlying storage for RDS instances using AWS KMS.

Configuration: Enable encryption when creating the RDS instance or modify an existing instance to enable encryption.

Least Amount of Changes:

Both EBS and RDS support seamless encryption with AWS KMS, requiring minimal changes to the existing infrastructure.

Enables compliance with regulatory requirements without modifying the application.

Operational Efficiency: Using AWS KMS for both EBS and RDS ensures a consistent, managed approach to encryption, simplifying key management and enhancing security.

AWS Lambda for Operational Efficiency:

AWS Lambdais a serverless compute service that allows you to run code without provisioning or managing servers. It automatically scales based on the number of invocations and eliminates the need to maintain and monitor EC2 instances, making it far more operationally efficient compared to running a cron job on EC2.

By using Lambda, you pay only for the compute time that your function uses. This is especially beneficial when dealing with lightweight tasks, such as scanning a DynamoDB table and sending email messages once a day.

Amazon DynamoDB:

DynamoDBis a highly scalable, fully managed NoSQL database. The table stores employee start dates, and scanning the table to find the employees who have a work anniversary on the current day is a lightweight operation. Lambda can easily perform this operation using theDynamoDB Scan APIor queries, depending on how the data is structured.

Amazon SNS for Email Notifications:

Amazon Simple Notification Service (SNS)is a fully managed messaging service that supports sending notifications to a variety of endpoints, including email. SNS is well-suited for sendingout email messages to employees, as it can handle the fan-out messaging pattern (sending the same message to multiple recipients).

In this scenario, once Lambda identifies employees who have their work anniversaries, it can use SNS to send the email notifications efficiently. SNS integrates seamlessly with Lambda, and sending emails via SNS is a common pattern for this type of use case.

Event Scheduling:

To automate this daily task, you can schedule the Lambda function usingAmazon EventBridge (formerly CloudWatch Events). EventBridge can trigger the Lambda function on a daily schedule (cron-like scheduling). This avoids the complexity and operational overhead of manually setting up cron jobs on EC2 instances.

Why Not EC2 or SQS?:

Option A & Bsuggest running a cron job on anAmazon EC2instance. This approach requires you to manage, scale, and patch the EC2 instance, which increases operational overhead. Lambda is a better choice because it automatically scales and doesn’t require server management.

Amazon Simple Queue Service (SQS)is ideal for decoupling distributed systems but isn’t necessary in this context because the goal is to send notifications to employees on their work anniversaries. SQS adds unnecessary complexity for this straightforward use case, whereSNSis the simpler and more efficient solution.

AWS References:

AWS Lambda

Amazon SNS

Amazon DynamoDB

Amazon EventBridge

Summary:

UsingAWS Lambdacombined withAmazon SNSto send notifications, and scheduling the function withAmazon EventBridgeto run daily, is the most operationally efficient solution. It leverages AWS serverless technologies, which reduce the need for infrastructure management and provide automatic scaling. Therefore,Option Cis the correct and optimal choice.

Amazon EventBridge is the best answer because it provides a managed event bus for routing messages between loosely coupled microservices and includes native event filtering and event archive capability. The company specifically needs message-based communication and a 30-day archive with the least development effort. EventBridge archives allow events on an event bus to be retained and replayed later, so no custom S3 archival pipeline or queue-retention workaround is required. SNS with SQS can distribute messages, but archiving messages for exactly this use case would require extra design and development. API Gateway with Lambda introduces unnecessary custom routing logic and operational complexity. EventBridge directly satisfies routing, filtering, and archiving in one managed service.

The most secure way to grant an external vendor’s AWS-hosted automation tool access into a company AWS account is to use cross-account IAM role assumption. Option A follows the standard AWS pattern: the company creates an IAM role in its own account that has only the permissions the vendor needs, and the role’s trust policy allows the vendor’s IAM role (in the vendor’s AWS account) to assume it. This approach avoids creating long-lived credentials in the company account and supports least privilege, auditing, and easy revocation.

With role assumption, the vendor continues to authenticate in its own AWS account and uses AWS STS to obtain temporary credentials when accessing the company account. Temporary credentials reduce exposure compared to access keys because they expire automatically and can be constrained with session duration, external IDs (where appropriate), and conditions. The company retains full control over permissions through the role policy, and CloudTrail can record AssumeRole events and subsequent API activity for auditing.

Option B is less secure because it creates an IAM user in the company account and would typically require managing long-lived credentials for the vendor tool, increasing the risk of leakage and ongoing operational overhead. Option C is not valid because IAM users are not shared across accounts; you cannot “add” a user from another account into an IAM group in your account. Option D is incorrect because “AWS account” is not a typical IAM identity provider type for this purpose; cross-account access is done through role trust policies, not by creating an IdP with an AWS account ID and username.

Therefore, A is the most secure solution because it uses short-lived credentials, enforces least privilege, centralizes control in the company account, and provides strong auditability without issuing permanent access keys.

Amazon RDS Proxy is designed to manage a large number of database connections from applications, especially serverless applications that can scale quickly. It improves application availability and scalability by pooling and sharing established database connections. This reduces the overhead of database connections and prevents overload during traffic spikes.

Amazon EFS provides a shared, fully managed, POSIX-compliant file system that can be mounted by all EC2 instances. Any update made to the file system is immediately visible to all instances, ensuring every new instance has the latest product manuals without delay.

EFS automatically scales storage and throughput, meeting high-demand conditions with no application changes required.

S3 requires instances to download files locally, causing delay and stale data issues (Options B and D). Instance store volumes (Option A) are ephemeral and not shared, making them unsuitable for consistent data distribution.

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Amazon ECS with Application Auto Scaling, an Application Load Balancer, and CloudFront is the strongest architecture because it supports scale, high availability, and lower operational overhead while allowing the company to reuse the existing application code through containerization. The ALB distributes traffic across ECS tasks and supports health checks. ECS Service Auto Scaling automatically adjusts running tasks based on demand, allowing the application to handle millions of requests. CloudFront improves global delivery by caching content and routing users through edge locations. A self-managed Kubernetes cluster in one Availability Zone is not highly available and creates unnecessary management work. API Gateway and Lambda would require application redesign. Keeping the origin on premises does not meet the migration goal.

AWS Global Accelerator: This service provides a global fixed entry point to your applications and optimizes the path to your application through the AWS global network, reducing latency and improving performance.

Accelerated TCP Connections:

Global Accelerator uses the AWS global network to route traffic to the nearest edge location, improving the performance and reliability of your live streams.

It provides static IP addresses that act as a fixed entry point to your application, simplifying DNS management.

High-Quality Streams:

By leveraging Global Accelerator, reporters can send live streams with the highest quality and low latency.

This service automatically reroutes traffic to the nearest available AWS Region, ensuring consistent performance even during traffic spikes or failures.

Operational Efficiency: Using Global Accelerator simplifies the network setup and provides an optimized path for live streams without the need for complex configurations, making it an efficient solution for real-time streaming applications.

Amazon RDS Proxyis the correct answer because it is specifically designed to improve connection handling for relational databases, including Aurora. AWS documentation explains that RDS Proxy providesconnection pooling, helps handleunpredictable surges in database traffic, and automatically determines the current Aurora writer instance. That reduces the stress of large numbers of short-lived connections and improves application behavior during failover events because clients reconnect through the proxy rather than directly to database endpoints. Switching database engines would be unnecessary and disruptive. DAX is for DynamoDB, not Aurora. Therefore, placingRDS Proxyin front of the Aurora cluster is the most direct way to reduce connection pressure and improve failover behavior. (AWS Documentation)

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Amazon S3 Object Lock is the AWS feature designed for WORM storage. AWS documentation says Object Lock helps prevent objects from being deleted or overwritten for a fixed amount of time or indefinitely and supports a WORM model. In compliance mode, even an administrator cannot shorten or remove the retention period before it expires, which is critical for confidential medical records and regulatory retention. Setting a 1-year retention period satisfies the minimum retention requirement, and IAM policies can still control which approved users are allowed to upload new objects. MFA Delete and ordinary IAM policies do not provide the same immutable WORM guarantees. A custom Lambda-based approach would add unnecessary complexity and still would not be the native compliance-oriented control that S3 Object Lock provides.

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Amazon SQS FIFO queues are built for workloads that require both message ordering and exactly-once processing behavior. AWS documentation states that FIFO queues preserve first-in, first-out order and support deduplication so duplicate messages are not introduced within the deduplication interval. That directly satisfies the requirement for exact order and exactly-once semantics. SNS alone is a pub/sub notification service, but it does not by itself provide this exact combination as simply as an SQS FIFO queue. Standard queues allow at-least-once delivery and can deliver messages out of order, so they do not meet the requirement. MSK could be engineered to solve the problem, but it introduces far more operational overhead than a managed queue service. For the most operationally efficient serverless design, SQS FIFO is the correct answer.

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AWS WAF Bot Control is the best fit because the problem is abusive automated traffic submitting unnecessary requests and consuming compute resources. AWS documents that the Bot Control managed rule group is specifically designed to identify and manage bot traffic, including high-confidence bot signatures and common bot categories. This is more targeted than maintaining custom IP blocks and more directly aligned to the behavior described than general IP reputation controls. AWS Shield focuses on DDoS protection, not detailed application-layer bot categorization. Therefore, associating a WAF web ACL with the ALB and enabling Bot Control is the most appropriate solution.

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A VPC peering connection with proper route table entries provides private IP connectivity between EC2 instances in separate VPCs. This keeps database traffic off the public internet and satisfies the private communication requirement. To make the traffic secure in transit, the MySQL instance should use an SSL certificate so the application can establish encrypted database connections. RDS Proxy is not valid because the database is self-hosted on EC2, not Amazon RDS. Allowing a public IP address would violate the private traffic requirement. A network ACL also cannot reference a security group ID, so option E is not a valid control. The correct combination is private VPC-to-VPC routing plus database-level encryption in transit.

Comprehensive and Detailed 250 to 300 words of Explanation (AWS documentation-based, no links):

Routing requests to the “appropriate microservices” implies Layer 7 (HTTP/HTTPS) routing such as host-based or path-based rules (for example, /customers to one service and /orders to another). In EKS, the most direct and cost-efficient way to provide this style of routing is to use Kubernetes Ingress with the AWS Load Balancer Controller to provision an Application Load Balancer (ALB). An ALB natively supports HTTP/HTTPS request routing features (paths, hosts, headers), which map cleanly to microservices patterns and reduce the need for additional infrastructure components.

A Network Load Balancer (NLB) (Option A) is primarily Layer 4 and is best for TCP/UDP/TLS pass-through and ultra-high performance. It does not provide the same native HTTP path-based routing behavior required to steer requests between microservices based on URL structure, so it often forces you to add another routing layer (like an in-cluster ingress gateway), which can increase cost and operational complexity.

Option C is not an appropriate request routing mechanism; Lambda is compute, not an ingress/routing layer for EKS. Option D (API Gateway) can front services, but for simple microservice routing into EKS it typically adds per-request costs and additional configuration compared with using an ALB that is purpose-built for HTTP load balancing and routing. API Gateway is a great fit for API management features (throttling, usage plans, keys, transformations), but those are not requirements here.

Therefore, B is the most cost-effective and architecturally aligned solution for HTTP routing across EKS-hosted microservices using managed AWS-native ingress integration.

EBS gp3 volumes allow you to independently configure IOPS and throughput, up to 16,000 IOPS, regardless of the volume size, and at a lower cost compared to io1/io2 provisioned IOPS volumes. This meets the requirement for cost-effective, predictable IOPS performance for Amazon RDS for PostgreSQL.

AWS Documentation Extract:

" With gp3 volumes, you can provision performance independent of storage capacity, up to 16,000 IOPS. This allows for cost-effective scaling for applications that require high performance at a lower price point compared to io1. "

(Source: Amazon EBS documentation, gp3 Volumes)

A: gp2 ties IOPS to volume size; 5 TiB is wasteful if only 15,000 IOPS are needed.

B: io1 works but is significantly more expensive than gp3 for most workloads.

D: Magnetic volumes do not support high IOPS.

A Network Load Balancer operates at Layer 4 (TCP/UDP/TLS) and is optimized for high performance and static IP use cases. While NLB target groups can perform health checks, they are typically oriented around basic reachability and do not provide the same application-layer (Layer 7) visibility as an Application Load Balancer (ALB). The problem statement says the NLB is “not detecting HTTP errors,” which indicates the health signal needs to be based on an HTTP endpoint that can reflect application correctness (for example, returning specific HTTP status codes).

Replacing the NLB with an ALB enables true HTTP/HTTPS health checks against a URL path, including interpretation of HTTP response codes. This is the cleanest managed approach to detect application-layer failure modes that still allow TCP connections but produce bad HTTP responses. Once the ALB detects targets as unhealthy, the target group health status can be used by an Auto Scaling group to take action. With appropriate health check configuration (and, commonly, using ELB health checks as a signal), Auto Scaling can replace unhealthy instances automatically, improving availability without custom scripts.

Option A is misleading: NLB does not provide the same HTTP-aware request routing and rich L7 features; even if an NLB health check is configured, it does not address the broader need for application-layer detection and remediation as directly as ALB. Option B violates the “no custom scripts” requirement. Option D reacts to UnhealthyHostCount, but if the NLB isn’t marking hosts unhealthy for HTTP error cases, the metric won’t reliably trigger replacement; it also still depends on the NLB’s limited visibility into HTTP failures.

Therefore, C best meets the requirement by shifting to ALB for application-layer health checks and using Auto Scaling to replace unhealthy instances automatically.

Amazon S3 and AWS Lambda form a classic serverless decoupling pattern for upload-and-process workflows. AWS documents that Amazon S3 can publishevent notificationswhen objects are created and that these events can invoke aLambda functionfor processing. This design automatically scales for high upload rates, durably stores the original images in S3, and cleanly separates upload from resize processing. Storing processed results in a second S3 bucket is also a common pattern that keeps originals and derivatives separate. The EC2 and EFS options add more operational work and do not provide the same event-driven elasticity.

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AWS Backup supports cross-Region backup for Amazon EFS, allowing automated, scheduled backups and replication to another Region. This managed service simplifies backup management and ensures data resilience without the need for custom scripts or manual processes

Amazon GuardDuty includes RDS Protection that “monitors and profiles access to your Amazon Aurora and Amazon RDS databases” to detect threats such as suspicious login attempts, brute-force activity, and anomalous authentication patterns. GuardDuty can be enabled organization-wide in AWS Organizations with a delegated administrator to centralize findings for all member accounts, minimizing operational overhead. Findings include context like source IP, user, and DB instance, and integrate with Amazon EventBridge for alerting and automated response. SCPs (A) enforce or deny API permissions but do not provide detection/analytics. Exporting general logs (C) requires building and maintaining custom parsing/analytics pipelines. CloudTrail (D) records AWS control-plane API calls and does not log database-level login attempts. Therefore, enabling GuardDuty RDS Protection across the org provides the most operationally efficient, managed detection of abnormal failed and incomplete login attempts.

Because the application is public and serves global customers with dynamic IP addresses, the web tier must allow HTTPS traffic from0.0.0.0/0on port 443. For the database tier, the secure design is to allow MySQL access only from theweb tier’s security group, not from the internet. AWS RDS documentation explains that you can specify another VPC security group as the source for the DB security group, which allows application servers to connect without exposing the database publicly. That makes A the correct configuration. Options B and C do not work well for global dynamic users, and D exposes the database to the internet.

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Lambda supports mounting an Amazon EFS file system inside your function to store larger dependencies beyond the 250 MB layer quota.

EFS automatically encrypts data in transit using TLS.

“You can configure your Lambda function to mount an Amazon EFS file system, enabling your function to access large amounts of data or large dependencies.”

“Amazon EFS automatically encrypts all data at rest and in transit.”

— Lambda with Amazon EFS

This is the least operational overhead approach.

Amazon S3 Intelligent-Tiering is designed for unknown or unpredictable access patterns, automatically moving objects to the most cost-effective tier without performance impact.

It is ideal when you do not know object size or access frequency.

S3 Standard (Option B) works but costs more.

S3 One Zone-IA and Glacier Deep Archive (Options D and A) are not appropriate because data is frequently accessed for processing and persists only 24 hours.

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Lambda@Edge allows you to run functions at CloudFront edge locations, enabling modifications to content before it ' s delivered to users, including compression — which directly reduces data transfer cost.

“Lambda@Edge can be used to compress or modify your content before delivering it to end users, which reduces the amount of data transferred.”

— Lambda@Edge Use Cases

Since code modifications aren’t allowed, using Lambda@Edge is a non-invasive way to:

Compress responses.

Reduce transfer size = lower CloudFront cost.

Incorrect Options:

B: S3 Transfer Acceleration improves speed, not cost.

C: Caching doesn’t help if content is always unique (single-use).

D: Multipart uploads help with large file uploads, not transfers.

AWS documentation states that workloads running 24/7 should use Reserved Instances or Savings Plans for the lowest cost. Therefore, the frontend nodes, which always run, should use Reserved Instances.

The backend nodes process asynchronous, restartable jobs, which makes them ideal for EC2 Spot Instances, the most cost-effective compute option for interruption-tolerant workloads.

Fargate (Options A and D) is significantly more expensive for large compute usage. Spot Instances cannot be used for critical frontend nodes (Option C).

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Compute Savings Plansoffer the most flexible and cost-effective solution for the production instances, as they provide significant savings (up to 66%) for both EC2 and AWS Lambda usage, while allowing flexibility in the type of instance family, size, and even region. For nonproduction instances, usingOn-Demand Instancesensures you only pay for the instances when they are running, and shutting them down during off-hours further optimizes cost.

Key AWS features:

Compute Savings Plans: Provide savings based on consistent usage, making it ideal for production environments with steady load.

On-Demand Instances: Suitable for nonproduction environments that are used intermittently. Shutting them down when not in use avoids unnecessary costs.

AWS Documentation: According to AWS ' s cost optimization best practices, using a combination of Savings Plans for production and On-Demand Instances for nonproduction environments that are used sparingly results in optimal cost savings??.

Using S3 event notifications to trigger AWS Lambda for file processing is a cost-effective and serverless solution. Lambda scales automatically with upload volume, and processing each file takes less than 5 seconds, fitting within Lambda ' s execution time.

Option A:AWS AppSync is designed for GraphQL APIs and is not suitable for file processing.

Option C:Kinesis is overkill and more expensive for this use case.

Option D:Running an EC2 instance incurs ongoing costs and is less flexible compared to Lambda.

AWS Documentation References:

Amazon S3 Event Notifications

AWS Lambda Overview

Option Ais the simplest solution, using DynamoDB Streams and Lambda for real-time ingestion into S3.

Options B, C, and Dadd unnecessary complexity with Data Firehose or Kinesis.

To process each form exactly once and ensure no data is lost, using an Amazon SQS FIFO (First-In-First-Out) queue is the most appropriate solution. SQS FIFO queues guarantee that messages are processed in the exact order they are sent and ensure that each message is processed exactly once. This ensures data consistency and reliability, both of which are crucial for processing user-submitted forms without data loss.

SQS acts as a buffer between the web application server and the worker tier, ensuring that submitted forms are stored reliably and forwarded to the worker tier for processing. This also decouples the application, improving its scalability and resilience.

Option B (API Gateway): API Gateway is better suited for API management rather than acting as a message queue for form processing.

Option C (SQS Standard Queue): While SQS Standard queues offer high throughput, they do not guarantee exactly-once processing or the strict ordering needed for this use case.

Option D (Step Functions): Step Functions are useful for orchestrating workflows but add unnecessary complexity for simple message queuing and form processing.

AWS References:

Amazon SQS FIFO Queues

Decoupling Application Tiers Using Amazon SQS

AWS WAF has limits on how much of an HTTP request body it can inspect. When requests exceed the inspectable size, AWS WAF treats the body as oversize relative to the configured inspection limits, which can lead to rules not evaluating the entire body content. If suspicious payloads are embedded beyond the inspected portion of a large POST request (for example, > 8 MB), WAF cannot reliably detect them purely through body inspection rules.

Given this constraint, the most effective way to “ensure” proper protection is to implement an oversize handling strategy using AWS WAF rule logic: block oversized requests by default and then explicitly allow oversized requests only from known legitimate sources. Option A accomplishes this by adding a rule that blocks oversize requests (so attackers cannot bypass inspection by sending very large bodies) and a higher-priority allow rule to permit large requests from trusted hosts (for example, specific known partners, internal CIDRs, or authenticated upstream systems). This design reduces the attack surface and provides deterministic behavior for requests that cannot be fully inspected.

Option B is incorrect because Shield Advanced is for DDoS protection and does not extend WAF’s request-body inspection size. Option C is unrelated: Content-Type can influence application parsing, but it will not overcome WAF body-size inspection limitations. Option D is not a practical fit for AWS WAF inspection because WAF evaluates requests at the edge/service layer; it does not natively “call Lambda to rewrite the request body” before WAF evaluates it. Any preprocessing would require a different architectural pattern (such as handling uploads out-of-band), which is beyond the scope and would add operational complexity.

Therefore, A is the correct approach: implement explicit oversized request handling by blocking by default and allowing only vetted large requests.

Comprehensive and Detailed 250 to 300 words of Explanation (AWS documentation-based, no links):

The company wants to increase security and reduce operational overhead for SQL Server relational databases. The most direct AWS managed service for SQL Server is Amazon RDS for SQL Server, which offloads routine database administration tasks such as provisioning, backups, patching (within managed service controls), monitoring integrations, and high availability management compared with running SQL Server on self-managed EC2.

Choosing Multi-AZ enhances availability and resilience by maintaining a synchronous standby in a separate Availability Zone with automated failover. This improves overall security posture and operational reliability because the platform handles common infrastructure failure scenarios without requiring custom clustering or manual intervention.

For encryption of sensitive data, integrating RDS with AWS KMS allows encryption at rest using KMS keys. Using an AWS managed key is operationally simple while still providing strong encryption controls, auditability, and centralized key management.

Option A still requires managing the database on EC2 (OS patching, SQL Server patching, backups, HA design, monitoring, recovery), which increases operational overhead significantly. Option C is not a database migration approach; S3 plus Macie does not provide a relational SQL Server engine for applications. Option D changes the data model by moving to DynamoDB and does not preserve SQL Server relational capabilities; CloudWatch Logs is not a data security control for database content.

Therefore, B best satisfies the goals: a managed relational database service (RDS for SQL Server) with built-in high availability (Multi-AZ) and encryption at rest via KMS, reducing ongoing operational work while improving security controls.

The Requester Pays feature in Amazon S3 allows the bucket owner to configure the bucket so that the requester, rather than the bucket owner, pays for data transfer and request costs. This is ideal for sharing large datasets with the public or with other AWS accounts when you want to minimize your own data transfer expenses.

Reference Extract from AWS Documentation / Study Guide:

" Requester Pays buckets allow you to configure the bucket so that the requester instead of the bucket owner pays the cost of the request and the data download from the bucket. "

Source: AWS Certified Solutions Architect – Official Study Guide, S3 Cost Management section.

Amazon CloudFront is a global content delivery network (CDN) that caches and distributes content to users with low latency. By setting the existing ALB as the origin, CloudFront can cache dynamic and static content closer to users worldwide, improving performance and reducing the load on the application servers. This is the most cost-optimized and AWS-recommended way to globally serve dynamic content for web applications.

Reference Extract:

" CloudFront accelerates delivery of both static and dynamic content, reducing latency and offloading origin resources by caching content at edge locations. "

Source: AWS Certified Solutions Architect – Official Study Guide, CloudFront and Global Application section.

For a large-scale multi-account AWS environment with many VPCs and centralized Direct Connect, AWS recommends using a Transit Gateway (TGW) architecture combined with a Direct Connect gateway (DXGW). This setup allows scalable, centralized connectivity between on-premises and multiple VPCs across accounts.

Step B: Creating a Direct Connect gateway and Transit Gateway in a central network account and connecting them via a transit VIF enables the on-premises network to access all connected VPCs.

Step D: Sharing the transit gateway with other accounts via AWS Resource Access Manager (RAM) allows the central TGW to attach VPCs in multiple accounts, simplifying multi-account connectivity.

Step F: To route cloud resources’ internet traffic back through the on-premises data center (for centralized egress), provisioning only private subnets and routing outbound internet traffic through NAT or firewall services in the data center is necessary. This requires configuring transit gateway and customer gateway routes appropriately.

Option A is partially correct in the use of Direct Connect gateway but association proposals are not scalable for hundreds of VPCs and accounts compared to transit gateway. Option C (internet gateway) is irrelevant here as traffic egress is required via on-premises data center, not directly to the internet. Option E (VPC peering) is not scalable for hundreds of VPCs.

Aurora blue/green deployments are specifically designed for:

Safely testing schema changes and database upgrades in an isolated environment (green) without impacting production (blue).

Performing a fast, low-downtime switchover once testing is complete and validated.

In this pattern:

The blue environment is the current production database.

The green environment is a synchronized copy used for testing changes.

You apply schema changes to the green environment, run tests, and when ready, perform a managed switchover that minimizes downtime and risk.

Why others are not ideal:

A: A separate staging cluster allows testing but does not provide automated, low-downtime synchronization and switchover.

B: Aurora read replicas are for read scaling; schema changes on replicas are not supported in the way described, and promotion alone doesn’t solve controlled testing and replication of changes.

D: Moving to DynamoDB changes database engines and data models entirely, and does not match the requirement to keep using Aurora MySQL.

Amazon S3 Transfer Acceleration is designed specifically to speed up long-distance uploads and downloads to an S3 bucket by using globally distributed CloudFront edge locations and optimized AWS network paths. Because users are located worldwide and upload images to one centralized S3 bucket, Transfer Acceleration directly addresses the performance bottleneck. The important detail is that clients must use the S3 Accelerate endpoint; simply enabling Transfer Acceleration but continuing to use the standard endpoint would not provide the acceleration benefit. CloudFront is useful for caching and accelerating content delivery to users, but it is not the best answer for improving global upload speed into a centralized S3 bucket.

The correct answer isAbecause the application is aglobal Voice over IPworkload that needslow latency,high availability, andautomated failover across AWS Regions.AWS Global Acceleratoris specifically designed to improve the availability and performance of global applications by routing user traffic over the AWS global network to the optimal healthy endpoint. It usesstatic Anycast IP addresses, which means users connect through fixed IP addresses that do not depend on client-side DNS or IP address caching behavior.

This is especially valuable for latency-sensitive applications such as Voice over IP, where rapid routing decisions and fast failover are critical. Global Accelerator continuously monitors endpoint health and can automatically direct traffic to healthy endpoints in another AWS Region if a failure occurs. This supports the requirement for cross-Region failover with minimal disruption.

Option B is incorrect becauseRoute 53 geolocation routingdirects traffic based on user location, but DNS-based routing can be affected by client-side caching and does not provide the same performance acceleration or fast failover behavior as Global Accelerator. Option C is incorrect becauseAmazon CloudFrontis primarily a content delivery network for HTTP and similar content distribution scenarios, not the preferred service for real-time Voice over IP traffic. Option D is incorrect because anApplication Load Balancerdoes not by itself provide global routing or multi-Region failover.

AWS best practices for global, latency-sensitive applications recommendAWS Global Acceleratorwhen the goal is to improve performance, use the AWS backbone network, and provide health-based failover without depending on DNS cache expiration. Therefore,AWS Global Accelerator with health checksis the best solution.

Why Option C is Correct:

NAT Gateway: Allows private subnets to access the internet for outbound requests while preventing inbound connections.

High Availability: Deploying NAT gateways in both AZs ensures fault tolerance.

Shared Route Table: Simplifies routing configuration for private subnets.

Why Other Options Are Not Ideal:

Option A: Creating separate route tables for each subnet adds unnecessary complexity.

Option B: Internet gateways allow inbound access, violating the requirement to block public IPv4 access.

Option D: Egress-only internet gateways are designed for IPv6, not IPv4.

AWS References:

Amazon VPC NAT Gateway:AWS Documentation - NAT Gateway

Amazon Kinesis Data Firehose (now known as Amazon Data Firehose) supports near-real-time streaming, with built-in support to:

Invoke AWS Lambda functions for transformation.

Store data directly into Amazon S3 in desired formats like Apache Parquet.

“You can use Data Firehose to transform the data before delivering it, by invoking a Lambda function. You can convert to formats such as JSON or Apache Parquet before storing it into S3.”

— Amazon Data Firehose Developer Guide

Why not the others?

B: Kinesis Data Streams requires more operational overhead than Firehose.

C: DataSync is for file movement—not stream processing.

D: SQS isn’t designed for streaming and transformation pipelines.

AWS best practices strongly recommend enabling MFA on the root user, but they also emphasize planning for MFA device loss. AWS allows the configuration of multiple MFA devices for the root user, which provides redundancy and ensures continued access in disaster scenarios. Option B directly addresses the requirement by enabling a backup authentication method without weakening security controls.

Adding multiple MFA devices ensures that if one device is lost, damaged, or unavailable, the organization can still authenticate securely using the secondary device. This approach maintains strong security while eliminating the risk of permanent root account lockout. It also avoids time-consuming recovery processes that require contacting AWS Support and proving account ownership.

Option A is not sufficient because IAM administrator accounts do not replace root access and cannot perform certain root-only actions. Options C and D are not feasible because new administrator accounts or policy changes cannot be made if root access is already lost.

Therefore, B is the correct and AWS-recommended solution to ensure uninterrupted, secure access to the root account while maintaining MFA protection.

Amazon ECS on AWS Fargate: AWS Fargate is a serverless compute engine for containers that works with Amazon ECS. It allows you to run containers without managing servers or clusters.

Amazon EFS: Amazon Elastic File System (EFS) provides a simple, scalable, fully managed elastic NFS file system for use with AWS Cloud services and on-premises resources. It can be mounted to ECS tasks running on Fargate, allowing containers to access a shared file system with standard file system semantics, including OS-level permissions.

Amazon Data Lifecycle Manager (DLM) automates the creation, retention, and deletion of EBSsnapshots. This allows organizations to define policies that ensure snapshots are only kept as long as needed, reducing costs automatically and minimizing manual effort. AWS recommends using DLM for optimizing storage and managing backup lifecycle with minimal overhead.

Amazon EFS provides a fully managed, highly available, and shared file system that can be mounted by instances across multiple Availability Zones. This ensures consistency of files between EC2 instances and avoids replication issues. EBS volumes, in contrast, are AZ-scoped and not designed for multi-instance sharing. Options A and B rely on custom replication or manual file handling, which increases operational overhead and risks inconsistencies. Option D does not solve the shared access and consistency requirement. By migrating storage to EFS, both EC2 instances will read and write to the same storage system, ensuring that users always access the latest files without 404 errors.

AWS Budgets supports budget actions that can automatically apply controls when a threshold is reached. In this case, because the accounts are non-production, it is appropriate to enforce a hard control by applying an SCP to the OU to deny additional usage and to stop running EC2 instances through a notification-driven workflow. AWS documentation describes AWS Budgets as the service for setting cost thresholds and taking automated actions, which makes it more appropriate than Cost Explorer reporting, CloudWatch alarms, or Cost Anomaly Detection for direct budget enforcement. Since the requirement is to prevent the team from exceeding the project budget, the budget-action-based control is the strongest solution.

To make the application highly available across regions:

Deploy the application in a different region using a newECS clusterandALBto ensure regional redundancy.

UseRoute 53 failover routingto automatically direct traffic to the healthy region in case of failure.

UseDynamoDB Global Tablesto ensure the database is replicated and available across multiple regions, supporting read and write operations in each region.

Option D (EKS cluster in the same region): This does not provide regional redundancy.

Option E (Global Secondary Indexes): GSIs improve query performance but do not provide multi-region availability.

Option F (PrivateLink): PrivateLink is for secure communication, not for cross-region high availability.

AWS References:

DynamoDB Global Tables

Amazon ECS with ALB

Comprehensive and Detailed Step-by-Step Explanation:

The requirement is toprevent data deletion by any user, including administrators, for 7 years while allowing automatic deletion afterward.

S3 Object Lock in Compliance Mode (Correct Choice - C)

Compliance mode ensures that even the root user cannot delete or modify the objects during the retention period.

After 7 years, the S3 Lifecycle policy automatically deletes the objects.

This meets bothimmutability and automatic deletionrequirements.

Governance Mode (Option B - Incorrect)

Governance mode prevents deletion,but administrators can override it.

The requirement explicitly states thateven administrators must not be able to delete the data.

S3 Bucket Policy (Option A - Incorrect)

An S3 bucket policy candeny deletes, but policies can be modified at any time by administrators.

It does not enforce strict retention like Object Lock.

S3 Batch Operations Job (Option D - Incorrect)

A legal hold does not have an automatic expiration.

Legal holds must be manually removed, which is not efficient.

Why Option C is Correct:

S3 Object Lock in Compliance Mode prevents deletion by all users, including administrators.

The S3 Lifecycle policy deletes the data automatically after 7 years, reducing operational overhead.

Comprehensive and Detailed 250 to 300 words of Explanation (AWS documentation-based, no links):

The requirements are straightforward: expose the Lambda microservice through an HTTPS endpoint and authenticate calls using IAM. Lambda function URLs are a built-in feature that provides a dedicated HTTPS endpoint for a Lambda function without requiring API Gateway, ALB, or CloudFront. When configured with the authentication type AWS_IAM, the endpoint requires requests to be signed with AWS Signature Version 4 and authorized by IAM policies. This directly satisfies the “must use IAM to authenticate calls” requirement with the least architectural complexity.

Option A can also secure an endpoint with IAM, but it proposes using a Lambda authorizer, which is typically used for custom authorizers (JWT/OAuth/Cognito/external identity). For IAM authentication in API Gateway, you generally use IAM authorization on the method, not an authorizer function. Also, API Gateway REST APIs introduce additional service configuration and per-request costs when a simpler managed option exists that meets the requirements.

Options C and D are not appropriate. Lambda@Edge and CloudFront Functions run at CloudFront edge locations with different programming and deployment models; they are designed for CDN request/response manipulation, not as the primary mechanism to expose a regional Lambda microservice endpoint with IAM authentication. CloudFront Functions in particular is for lightweight JavaScript at the edge and does not provide a native “AWS_IAM authentication type” for invoking an origin Lambda as a microservice endpoint.

Therefore, B is the cleanest and most secure fit: a native HTTPS endpoint backed by Lambda, protected with IAM-based SigV4 authentication.

AWS Backup offers centralized management, scheduling, and retention of backups for supported AWS services including Amazon DynamoDB. It enables compliance retention with minimal management.

From AWS Documentation:

“AWS Backup provides centralized backup management across AWS services, including DynamoDB. You can define backup plans, schedules, and retention policies to meet business or regulatory requirements.”

(Source: AWS Backup Developer Guide – Backing up DynamoDB Tables)

Why B is correct:

Automatically manages backup scheduling and retention (7 years).

Centralized compliance monitoring via AWS Backup Audit Manager.

Fully managed and requires no custom automation.

Why others are incorrect:

A: PITR is for continuous restore within 35 days, not long-term compliance retention.

C & D: Manual or Lambda-based backups require custom management and increase operational complexity.

As the number of VPCs grows, managing individual VPC connections becomes complex and unscalable. AWS Transit Gateway is specifically designed to act as a central hub that connects multiple VPCs and on-premises networks through Direct Connect.

Option B simplifies network architecture by allowing hundreds or thousands of VPCs to connect through a single gateway, reducing routing complexity and operational overhead. Transit Gateway supports scalable routing, centralized inspection, and simplified expansion.

The other options do not address network connectivity or scaling challenges. Therefore, B is the correct solution.

AWS S3 Multi-Region Access Points enable customers to use a single global endpoint for S3 bucket access across multiple AWS Regions, providing automatic routing to the nearest Region. This reduces public network congestion by directing user data to the closest S3 bucket and supports high availability with active-active configuration.

Cross-Region Replication ensures data is replicated between buckets in different Regions, meeting the failover and resilience requirements with minimal management overhead.

Option D aligns best with AWS’s recommended approach to resilient, low-latency, and simplified multi-Region S3 access.

Option A lacks the global endpoint and automatic failover. Option B incorrectly describes Multi-Region Access Points configuration and suggests global endpoints per Region, which is contradictory. Option C’s cross-account replication adds complexity and does not provide a single global endpoint.

AWS WAF is the correct service because AWS documents that it protects web applications at Layer 7 and defends against common web exploits such as SQL injection and cross-site scripting. Associating WAF with the ALB allows malicious requests to be filtered before they reach the EC2 instances, which minimizes application impact and avoids pushing inspection logic onto the hosts. CloudTrail, GuardDuty, and network ACLs are not the best tools for active application-layer request filtering against SQLi and XSS. Shield Advanced can add further protection for broader attack scenarios, but the key control in this answer is WAF on the ALB with rules that block malicious traffic patterns.

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Amazon S3 is the most scalable and cost-optimized object storage for large amounts of data. It integrates natively with Amazon SageMaker, which allows direct access to S3 data for machine learning training jobs without the need to copy data elsewhere. The S3 Intelligent-Tiering storage class further optimizes storage costs for data with unknown or changing access patterns, while maintaining immediate availability for ML training.

Copying to FSx for Lustre or EFS adds unnecessary complexity and cost unless ultra-high throughput POSIX file access is specifically required, which is not mentioned here.

AWS Documentation Extract:

" Amazon S3 provides cost-effective storage for ML data sets, and Amazon SageMaker can directly access data in S3. S3 Intelligent-Tiering automatically moves data between frequent and infrequent access tiers, optimizing costs for changing data access patterns. "

(Source: AWS S3 and SageMaker documentation)

A, D: FSx for Lustre or EFS may be used in specialized cases but are not cost-optimized for general large-scale ML data storage.

C: SageMaker notebook instance storage is not designed for large-scale data ingestion or long-term storage.

Amazon S3 Storage Lens with advanced activity metrics is the most operationally efficient answer because AWS documentation explicitly says you can use S3 Storage Lens advanced metrics to identify “cold” buckets, meaning buckets whose objects are no longer accessed or are accessed only rarely. That is exactly the requirement in the question. This avoids building a custom analytics workflow on top of CloudTrail or CloudWatch metrics. The standard S3 console does not provide the same purpose-built fleet-level analysis for cold-bucket identification. Athena and CloudTrail can be used for access analysis, but they require more setup, data handling, and query maintenance. S3 Storage Lens is the native managed feature for this storage-optimization scenario. (AWS Documentation)

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Amazon EMR instance fleets are the correct design because they provide the most flexible and operationally efficient way to launch clusters across different EC2 instance types, Availability Zones, and purchasing options. In this scenario, the company wants On-Demand Instances for core nodes, Spot Instances for task nodes, and memory optimized instances only where capacity is available. Instance fleets allow EMR to evaluate multiple subnets in multiple Availability Zones and provision capacity where the requested instance types and purchase models are available. Instance groups are more rigid because they are tied to a more fixed instance configuration. A single-subnet design also fails the Availability Zone flexibility requirement. Therefore, using EMR instance fleets across multiple subnets is the best answer.

For the web tier, the company needs multi-AZ scaling and high availability, which is best achieved with anAuto Scaling group across multiple Availability Zones behind an Application Load Balancer. AWS fault-tolerance guidance recommends distributing EC2 instances across multiple AZs and using Auto Scaling to maintain balance and resilience. For the database tier, the question specifically requires reduced MySQL read latency, so anAurora MySQL cluster with a reader instance in a separate AZis the stronger fit. AWS Aurora guidance recommends distributing the primary and reader instances across Availability Zones and notes that Aurora Auto Scaling can add reader instances for handling increased connectivity and workload. Together, B and C deliver scalability, HA, and better read performance.

============

To improve read performance for a MySQL-based RDS database under load, you can:

Use Read Replicas: Amazon RDS supports MySQL read replicas, which help offload read operations from the primary database, improving performance during high traffic.

Use ElastiCache (Memcached): Adding an in-memory cache layer using Amazon ElastiCache reduces the load on the RDS instance by serving frequent queries directly from memory, especially when data is not updated often.

Option A (AWS WAF) is for web security, not database performance. Option D relates to storage optimization, not query latency. Option E would require re-architecting from relational to NoSQL, which is unnecessary and disruptive.

The requirements emphasize high availability across multiple Availability Zones, automatic recovery, and least operational overhead. The simplest way to achieve this for containerized microservices is to use a fully managed container orchestration service with serverless compute. Amazon ECS with the Fargate launch type provides exactly that.

With ECS Fargate, AWS manages the underlying compute infrastructure (no EC2 instances to provision, patch, scale, or secure at the OS level). You define task definitions and services, and ECS schedules tasks across Availability Zones based on your networking configuration (multiple subnets in different AZs). If a container fails, ECS service scheduling automatically replaces it, fulfilling the “recover from failures” requirement. Fargate also integrates with load balancing, CloudWatch logging, and scaling policies, reducing the operational burden of keeping the platform healthy.

Option A (ECS on EC2) is still managed orchestration, but it requires managing the EC2 capacity layer: AMI updates, instance patching, cluster capacity planning, and instance scaling. Option B (EKS with self-managed nodes) typically carries even more operational responsibility because you manage node groups, upgrades, and Kubernetes operational complexity in addition to the underlying instances. Option D is the highest operational overhead because it lacks managed scheduling and self-healing; you would need to build and maintain your own process manager and failover mechanisms.

Therefore, C is the best answer because it provides a managed, multi-AZ capable, self-healing container platform with minimal infrastructure management—matching the operational efficiency goal while maintaining high availability.

AWS recommends usingSystems Manager Session Managerinstead of direct SSH for administrative access because it provides browser-based or CLI-based access without bastion hosts and supports centralized audit logging. To allow private instances to reach Systems Manager without internet exposure, the VPC needs the appropriateinterface VPC endpoint. The managed instances also need the proper instance permissions, and AWS documentation points to theAmazonSSMManagedInstanceCorepolicy for that purpose. A gateway endpoint is not used for Session Manager, and attaching a user-facing Session Manager policy to the EC2 instances themselves is the wrong permission model. This makesB and Ethe most operationally efficient and secure combination. (AWS Documentation)

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Aurora Replicas: Provide read scalability and high availability. They allow offloading read traffic from the primary database instance.

AWS Global Accelerator: Provides improved availability and performance by routing user requests to the optimal endpoint using AWS’s global network.

“Aurora Replicas can be used to increase read scalability and availability.”

— Aurora Replicas

“AWS Global Accelerator improves the availability and performance of your applications with global users.”

— AWS Global Accelerator

Together, these enhance both the database and network layer resilience.

Amazon SQS is a fully managed message queuing service that reliably decouples and scales microservices, distributed systems, and serverless applications. By using SQS, microservices can communicate asynchronously, handle bursts of traffic, and avoid data loss by buffering messages until they are processed. Deploying the services on ECS with AWS Fargate further reduces operational overhead by removing the need to manage servers, allowing independent scaling of each microservice.

Reference Extract:

" Amazon SQS decouples application components and enables message durability and scaling. AWS Fargate removes the need to manage infrastructure, supporting independent scaling and minimal operational overhead. "

Source: AWS Certified Solutions Architect – Official Study Guide, Microservices and Messaging section.

Amazon Elastic File System (Amazon EFS) is a fully managed, elastic, shared file system that can be mounted concurrently by multiple EC2 instances across multiple Availability Zones. EFS automatically grows and shrinks as files are added or removed, providing seamless scalability for unpredictable and growing storage needs. It supports simultaneous access from multiple compute resources, making it ideal for applications where several EC2 instances must read and write to the same data set concurrently. EBS volumes cannot be shared across multiple Availability Zones, and S3 Glacier is intended for archival and infrequent access, not for active, hourly data analysis.

Reference Extract from AWS Documentation / Study Guide:

" Amazon EFS provides a scalable, fully managed elastic NFS file system for use with AWS Cloud services and on-premises resources. It can be mounted to many EC2 instances across multiple Availability Zones and is ideal for shared data scenarios. "

Source: AWS Certified Solutions Architect – Official Study Guide, Storage Solutions section; Amazon EFS User Guide.

Amazon EMR is the strongest fit here because AWS describes EMR as a service for processing, analyzing, transforming, and moving large amounts of data, and EMR supports running parallel steps for distributed processing. The question explicitly wantsparallel processingof large semistructured data in S3, which matches EMR well. AWS also documents a supported pattern forloading data from Amazon EMR to Amazon Redshift, and Redshift supports querying semistructured data, which makes EMR plus Redshift a natural enrichment workflow. Athena and Glue can be useful in some analytics patterns, but the requirement for parallel high-volume processing points most directly to EMR.

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AWS Storage Gateway stored volume gateway is designed for use cases where:

The primary data set remains on premises.

You want to maintain full local access to data with low latency.

You need asynchronous, secure replication and backup to AWS.

With stored volumes, you:

Map gateway storage volumes to local on-premises disks.

Present these volumes as iSCSI block devices to on-prem systems.

Storage Gateway then asynchronously backs up snapshots to Amazon S3, providing secure, durable offsite backup automatically.

Cached volume gateway (Option C) keeps the primary copy in AWS and only a subset cached locally, which does not meet the requirement to maintain full local access to all data.

Snowball and Snowball Edge (Options A and B) are primarily for bulk, one-time or periodic offline data transfer and do not provide an ongoing backup solution with continuous local access.

Amazon RDS Proxy is a fully managed database proxy for RDS that makes applications more scalable, more resilient to database failures, and more secure. RDS Proxy pools and shares database connections, allowing applications to open and close connections as needed without overwhelming the database. This is the recommended solution when the application cannot be modified to use connection pooling itself.

AWS Documentation Extract:

" Amazon RDS Proxy helps manage database connections to improve application scalability and performance. It pools connections and shares them among application clients, which can mitigate issues caused by opening and closing many database connections. "

(Source: Amazon RDS Proxy documentation)

A: Upgrading the instance does not solve connection inefficiency and can be cost-ineffective.

B: Increasing IOPS only helps if storage is a bottleneck, not if connections are the issue.

D: Multi-AZ improves availability, not connection management.

VPC Endpoint for S3: A gateway endpoint for Amazon S3 enables you to privately connect your VPC to S3 without requiring an internet gateway, NAT device, VPN connection, or AWS Direct Connect connection.

Configuration Steps:

In the VPC console, navigate to " Endpoints " and create a new endpoint.

Select the service name for S3 (com.amazonaws.region.s3).

Choose the VPC and the subnets where your EC2 instances are running.

Update the route tables for the selected subnets to include a route pointing to the endpoint.

Security Compliance: By configuring an S3 gateway endpoint, all traffic between the VPC and S3 stays within the AWS network, complying with the company ' s security regulations to avoid internet traversal.

Aurora Global Database is designed for low-latency cross-Region reads and disaster recovery for relational data.

Amazon S3 Cross-Region Replication (CRR) automatically replicates unstructured data to another Region, ensuring high availability and resilience.

“Aurora Global Database replicates your data with typical latency of less than 1 second to secondary AWS Regions.”

“Amazon S3 Cross-Region Replication automatically replicates every object uploaded to your bucket to a destination bucket in another AWS Region.”

— Aurora Global Database

— S3 Cross-Region Replication

This combination meets the multi-Region, high availability, fault-tolerant requirement for both relational and unstructured data.

Durable storage of incoming orders with buffering and ability to handle surges is exactly what Amazon SQS is designed for. SQS provides highly durable, scalable queues that decouple producers from consumers.

Centrally tracking workflow steps is a core use case of AWS Step Functions, which gives a visual workflow and state machine, tracks the state of each order, and can orchestrate calls to multiple microservices (in this case, Lambda functions).

Combining SQS + Step Functions + Lambda gives:

Durable queueing for orders (SQS).

Loose coupling and surge handling (SQS decoupling + auto-scaling Lambda).

Central orchestration and tracking of order-processing steps (Step Functions).

Why the other options are not correct:

A: SNS is a pub/sub service, not a durable work queue, and is not designed for “store-and-retry until processed” workloads in the same way SQS is.

C: SQS + EventBridge provides decoupling but no central, stateful workflow tracking; EventBridge is event routing, not workflow orchestration.

D: SNS + EventBridge still lacks durable order storage and explicit centralized workflow/state tracking.

The most effective way to reduce load on the web servers is to move the static video content toAmazon S3and deliver it throughAmazon CloudFront. CloudFront caches content at edge locations so repeated requests are served closer to users without repeatedly hitting the origin. AWS documentation also recommendsorigin access control OACto securely restrict direct access to the S3 origin and allow CloudFront to fetch the objects on behalf of viewers. ElastiCache is not a video-origin service, EFS would still keep the web servers in the delivery path, and File Gateway is for hybrid file access rather than internet content distribution. For high-traffic video delivery with the least origin load, S3 plus CloudFront with OAC is the correct design.

Express Workflows in AWS Step Functions are optimized for high-throughput, short-duration, and low-cost workflows. They are suitable for applications with large volumes of parallel and interdependent tasks. When paired with HTTP APIs from API Gateway, which are more cost-efficient than REST APIs, this setup offers scalability and cost-effectiveness.

In Amazon EKS, Kubernetes stores objects such as Secrets in the cluster’s etcd key-value store. By default, Kubernetes Secrets are base64-encoded and are not automatically encrypted at the application object level unless encryption is configured. Amazon EKS provides a managed capability to encrypt Kubernetes Secrets at rest in etcd using AWS Key Management Service (KMS). The requirement explicitly states that “all secrets that are stored in Amazon EKS must be encrypted in the Kubernetes etcd key-value store,” which maps directly to enabling EKS secrets encryption with a customer-managed KMS key.

Option B is exactly this: create a KMS key and enable EKS KMS secrets encryption on the cluster. With this enabled, EKS uses envelope encryption so that Secrets are encrypted when stored in etcd, and decrypt operations are controlled through KMS permissions. This is the standard, AWS-native method that fulfills the requirement without requiring application changes or external secret stores for the encryption-at-rest requirement in etcd.

Option A (Secrets Manager) is a strong service for secret lifecycle management and rotation, but it does not by itself guarantee that Kubernetes Secrets stored in etcd are encrypted unless EKS secrets encryption is also enabled or the cluster avoids storing secrets in etcd entirely. The question specifically targets etcd encryption. Option C is unrelated: the EBS CSI driver concerns persistent volumes, not etcd secret encryption. Option D concerns EBS volume encryption and a specific AWS-managed key alias used for EBS; it also does not address etcd encryption for Kubernetes Secrets.

Therefore, B is the correct solution because it directly enables encryption of Kubernetes Secrets within etcd using KMS.

The correct answer isCbecause the company already usesAmazon FSx for NetApp ONTAPand requires a disaster recovery solution in a secondary Region that preserves access through thesame protocols, specificallyCIFS and NFS. The most appropriate solution is to deploy a secondFSx for ONTAPfile system in the secondary Region and useNetApp SnapMirrorto replicate data between Regions. SnapMirror is built for ONTAP-based replication and is the native mechanism for efficient, storage-level disaster recovery.

This option provides the least operational overhead because it uses the capabilities already integrated into FSx for ONTAP rather than introducing another storage platform or custom replication tooling. It also preserves protocol compatibility, so applications in the recovery Region can continue to access data through CIFS and NFS without architectural changes.

Option A is incorrect because replicating data to Amazon S3 does not preserve native CIFS and NFS file shares. Option B can support recovery, but backups and restores are not the best fit for an active DR strategy where the secondary Region needs accessible replicated storage with the same protocols and lower recovery effort. Option D is incorrect because Amazon EFS does not provide CIFS/SMB support in the same way as FSx for ONTAP and would require a platform change.

AWS guidance for FSx for ONTAP disaster recovery favors usingSnapMirror replicationto another FSx for ONTAP deployment. This approach is protocol-compatible, efficient, and operationally simpler than building a custom DR workflow.

To securely access AWS services like S3 and Secrets Manager from a private VPC without using public IPs, interface VPC endpoints are required. These endpoints are accessible via private IP addresses. For the application to reach these endpoints, appropriate routes must be configured in the route table.

Amazon ECS on AWS Fargate with Amazon EFS is the best match because it combines managed container orchestration with shared persistent storage. AWS documentation explains that Amazon EFS volumes can be used with Amazon ECS so tasks can access the same persistent file system regardless of where they run. AWS also notes that EFS volumes are useful for horizontally scaled containerized applications that need shared storage, low latency, and high throughput. Lambda is a poor fit here because Lambda invocations have a maximum timeout of 15 minutes, while the question states processing can take up to 1 hour. Instance store volumes on ECS EC2 are local to the host and do not provide the centralized persistent repository the workload needs. Fargate plus EFS best satisfies performance, duration, and operational efficiency.

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Converting the existing DynamoDB table to aglobal tableprovides active-active replication and low-latency reads and writes in both Regions. DynamoDB global tables are specifically designed for multi-Region and multi-active use cases.

Option A:GSIs do not provide multi-Region replication or active-active capabilities.

Option B and D:Using DynamoDB Streams and custom replication is less operationally efficient than global tables and introduces additional complexity.

AWS Documentation References:

DynamoDB Global Tables

Tape Gateway is purpose-built for organizations that want tokeep their existing tape backup workflowswhile moving the tape infrastructure to AWS. AWS documentation states that Tape Gateway provides cloud-backed virtual tape storage and can archive tapes toS3 Glacier Flexible Retrieval or S3 Glacier Deep Archive. Because the company needs 10-year retention and wants the most cost-effective archive tier,Glacier Deep Archiveis the best fit. This approach also avoids redesigning the backup process, which is one of the explicit requirements. Snowball can move data in bulk, but it changes the workflow and the storage-class target in option C is not the lowest-cost long-term archive. Tape Gateway aligns directly with both operational continuity and archival economics.

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The correct answer isAbecause the company needs to rotatedatabase credentials every 30 dayswhile maximizing security and minimizing development effort.AWS Secrets Manageris the AWS service specifically designed to store, manage, and rotate secrets such as database usernames and passwords. It supportsautomatic rotationfor supported databases, includingAmazon Aurora MySQL, which makes it the most secure and operationally efficient solution.

With Secrets Manager, credentials are encrypted at rest, access can be controlled through IAM policies, and applications can retrieve secrets programmatically without embedding them in source code or configuration files. Automatic rotation reduces the risk associated with static credentials and helps meet compliance requirements with minimal manual work. Because rotation is built into the service, the development effort is significantly lower than creating and maintaining custom rotation logic.

Option B can work, but it requires building and operating a customLambda rotation function, which adds complexity compared with the native automation available in Secrets Manager. Options C and D are not best practices because storing credentials in environment files or configuration files increases security risk and does not provide a managed secrets lifecycle.

AWS security best practices recommend centralizing sensitive credentials inAWS Secrets Managerand enablingautomatic rotationwhenever possible. This improves security posture, reduces operational overhead, and aligns directly with compliance requirements for regular credential changes. Therefore, storing Aurora MySQL credentials inSecrets Managerwith30-day automatic rotationis the best solution.

Amazon Timestreamis purpose-built for storing and analyzing time-series data like telemetry.

Option Aleverages Timestream, SageMaker for ML, and QuickSight for visualization, meeting all requirements with minimal complexity.

Option Binvolves more complex DynamoDB-EMR integration.

Option Cuses Neptune, which is designed for graph databases, not telemetry data.

Option Dincorrectly uses Athena for visualization instead of QuickSight.

Amazon RDS for Oracle is a managed database service, which significantly reduces operational overhead compared to running Oracle on EC2 or on-premises. AWS Secrets Manager natively integrates with RDS and supports automatic, scheduled password rotation with minimal setup. You can configure the rotation schedule (including yearly), and Secrets Manager will handle the secure password storage and rotation workflow for you.

AWS Documentation Extract:

" AWS Secrets Manager helps you protect access to your applications, services, and IT resources without the upfront investment and on-going maintenance costs of operating your own infrastructure. You can configure automatic rotation for supported databases such as Amazon RDS for Oracle. "

(Source: AWS Secrets Manager documentation)

A, C, D: These solutions require custom scripting, Lambda, and alarms, leading to more operational overhead.

The optimal solution for low-latency global caching with disaster recovery and cross-Region replication is to use Amazon ElastiCache Global Datastore for Redis OSS.

A Global Datastore enables fully managed cross-Region replication and supports automatic failover by promoting read replica clusters in another Region.

ElastiCache ensures encryption in-transit and at-rest, meeting compliance and security requirements.

It ' s a fully managed AWS-native feature, reducing operational effort compared to setting up DMS-based or snapshot-based replication manually.

Other options (A, C, D):

Require manual setup and management (e.g., custom DMS pipelines, snapshots).

Do not offer real-time replication or failover without manual intervention.

???? Reference:

ElastiCache Global Datastore for Redis

Amazon Aurora global database is the best answer because AWS documents state that Aurora global database replicates data to secondary Regions using dedicated infrastructure, with latency typically under one second. That directly matches the requirement for near-real-time access in eu-west-2. AWS also notes that Aurora global database is intended for cross-Region reads with minimal lag and fast disaster recovery. Standard RDS cross-Region read replicas can help, but they are not positioned as the lowest-lag cross-Region option in the way Aurora global database is. DynamoDB global tables are excellent for globally distributed NoSQL workloads, but the question centers on database-backed dashboards with complex analytical queries, which aligns better with Aurora. For the most up-to-date cross-Region dashboard reads, Aurora global database is the strongest fit.

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Using Amazon SQS decouples the API from the database, allowing the system to handle write bursts without data loss. The queue buffers incoming requests, and AWS Lambda processes them asynchronously, writing to the RDS instance at a sustainable rate.

From AWS Documentation:

“Amazon SQS acts as a buffer between components that produce and consume data, allowing each to operate independently. You can use AWS Lambda to process messages from SQS and write them to other services such as Amazon RDS.”

(Source: Amazon SQS Developer Guide)

Why C is correct:

SQS absorbs write surges and ensures durable message retention.

Lambda scales automatically with message volume and reduces DB connections.

Prevents timeout errors by smoothing traffic spikes.

Why others are incorrect:

A: Scaling RDS vertically doesn’t address connection spikes.

B: Multi-AZ is for availability, not write throughput.

D: SNS is for fan-out message delivery, not queue-based buffering.

Using S3 gateway endpoints allows private and cost-free access to S3 without routing traffic through a NAT gateway. NAT gateway traffic incurs charges, especially when used across multiple Availability Zones.

By using an S3 gateway endpoint, EC2 instances in private subnets can access S3 directly without needing internet access, reducing both data transfer and NAT gateway costs.

Interface endpoints are more expensive and typically used for services like API Gateway or Systems Manager.

SSE-KMS (Server-side encryption with AWS Key Management Service) not only encrypts data at rest but also integrates with AWS CloudTrail to provide detailed logs of key usage — meeting the audit requirement.

“SSE-KMS provides the ability to audit key usage to see who used the key and when, via AWS CloudTrail.”

— Amazon S3 Encryption Documentation

Benefits:

Encryption with customer-managed or AWS-managed KMS keys

Audit trails of key usage events

Fine-grained access control

Incorrect Options:

A: SSE-S3 does not support auditing of key usage.

C: SSE-C does not integrate with CloudTrail or KMS.

D: Self-managed keys require external key infrastructure and custom audit logging.

S3 Intelligent-Tiering is designed for data with unknown or changing access patterns. It automatically moves objects between frequent and infrequent access tiers as needed, with no retrieval fees for accessing data in any tier, and no performance impact. Minimal management overhead is required because AWS manages all transitions automatically. This class is cost-optimized and meets all requirements listed.

AWS Documentation Extract:

" S3 Intelligent-Tiering is the only storage class that automatically moves data between frequent and infrequent access tiers when access patterns change, with no retrieval charges and no impact on performance. It is designed to optimize costs automatically when data access patterns are unpredictable. "

(Source: Amazon S3 documentation, Intelligent-Tiering storage class)

Other options:

B: Storage class analysis only provides recommendations, not actual storage tiering.

C & D: S3 Standard-IA and S3 One Zone-IA both have retrieval fees and may impact retrieval time and data durability.

Amazon DynamoDB is a serverless, NoSQL database that is fully managed, highly available, and scales automatically. It is ideal for data without a fixed schema and for use cases where fields can vary by user. DynamoDB Streams enables the capture of changes to table items in real time, which is ideal for triggering additional processing or workflows on data modifications.

Reference Extract from AWS Documentation / Study Guide:

" DynamoDB provides a scalable, highly available NoSQL database service for applications requiring flexible schema. DynamoDB Streams captures table activity for processing changes in real time. "

Source: AWS Certified Solutions Architect – Official Study Guide, DynamoDB and Serverless section.

Option Bensures the use of S3 Object Lock and Versioning to meet compliance for immutability. CloudFront enhances performance while a bucket policy ensures secure access.

Option Alacks immutability safeguards.

Option Cintroduces unnecessary complexity.

Option Dmisses out on additional security benefits offered by CloudFront.

Protecting an application from layer 7 (application layer) DDoS attacks is best achieved by using AWS WAF (Web Application Firewall), which provides customizable protection against common web exploits including DDoS attacks at the application layer. AWS WAF supports managed rule groups maintained by AWS, which offer robust, tested protections against OWASP top 10 vulnerabilities and common attack patterns without requiring extensive manual rule creation.

While AWS Shield Standard provides basic network-layer DDoS protection automatically at no additional charge, it does not offer application-layer filtering capabilities. Therefore, option A alone is insufficient.

Option B, involving only custom rules, requires significant operational overhead and expertise, whereas AWS managed rules offer a turnkey solution with ongoing updates from AWS security teams.

Option D, using CloudFront in front of the ALB, can provide additional protection benefits such as caching and geographic restrictions, but the question specifically asks for protecting against layer 7 DDoS on the ALB directly. CloudFront plus WAF is a valid enhanced solution, but the direct and recommended answer in AWS official documents is to use AWS WAF managed rules directly with ALB for application-level protection.

AWS Lake Formation provides centralized data access control, including fine-grained (column-level) permissions for data stored in S3 and accessed through services like Amazon Athena.

Using a Lake Formation blueprint to ingest data from Aurora MySQL into the data lake keeps ingestion and governance integrated. When QuickSight uses Athena as the data source, Athena enforces Lake Formation’s column-level permissions automatically. This allows the marketing team to see only the authorized subset of columns without custom access-control logic.

Options A, B, and C rely on manually limiting columns at ingestion time or using IAM or S3 bucket policies, which do not provide true column-level authorization for SQL queries and require significantly more manual work and maintenance.

The requirements focus on cost optimization, automatic lifecycle management, and throughput scaling based on file system size. Amazon EFS provides two throughput modes: bursting and provisioned. Bursting throughput automatically scales with the size of the file system, which directly aligns with the company’s needs.

Option C is correct because it combines two essential features. First, configuring lifecycle management to transition files from Standard to Infrequent Access (IA) after 30 days reduces storage costs for infrequently accessed data. Second, enabling automatic transition back to Standard storage upon access ensures that performance-sensitive reporting workloads are not negatively affected when older files are read.

Using bursting throughput mode allows throughput to grow naturally as the file system size increases, eliminating the need to manually manage or pay for fixed throughput levels. This is ideal for workloads with variable access patterns.

Option A incorrectly specifies provisioned throughput, which is designed for predictable, high-throughput workloads and incurs additional cost. Option B ignores lifecycle transitions. Option D does not account for automatic return to Standard storage, which could lead to suboptimal performance for accessed files.

Therefore, C provides the best balance of performance, cost efficiency, and minimal operational overhead.

AWS Outposts brings native AWS services (including Amazon EMR) on-premises, ideal when data residency or latency constraints require local processing.

You benefit from AWS’s managed services while meeting the requirement to keep data processing local.

AWS Transfer Family is a fully managed service that provides SFTP, FTPS, and FTP access directly to Amazon S3. It allows organizations to support legacy data transfer protocols without managing infrastructure. This approach gives the vendors a familiar SFTP interface, with files landing directly in S3, and requires minimal operational effort compared to managing EC2 servers or using gateways.

Reference Extract from AWS Documentation / Study Guide:

" AWS Transfer Family enables secure transfer of files directly into and out of Amazon S3 using SFTP, FTPS, and FTP, and is fully managed by AWS, significantly reducing operational overhead. "

Source: AWS Certified Solutions Architect – Official Study Guide, Data Migration and Transfer section.

Auto Scalingis the most effective solution for ensuring seamless scalability of a stateless application. Key points:

Dleverages Auto Scaling with a Spot Fleet for cost efficiency and attaches an ALB to distribute traffic.

A and Bdo not provide automated scaling and would require manual intervention to add more instances.

Cchanges the instance type but does not scale out horizontally, which is required here.

AWS Documentation Reference:

Amazon EC2 Auto Scaling

Using API Gateway and Lambda enables serverless handling of form submissions with minimal cost and infrastructure. When coupled with Amazon SNS, it allows instant email notifications without running servers, making it ideal for low-traffic workloads.

Spot Instances can be interrupted when AWS needs the capacity back. To reduce interruptions and improve availability, AWS provides the capacity-optimized allocation strategy.

Capacity-optimized strategy launches Spot Instances from the most available Spot capacity pools instead of the lowest-priced ones, reducing interruption rates.

By adding multiple instance types (e.g., using Instance Type Flexibility), the Auto Scaling group can launch instances in a broader set of pools, improving the chance that capacity is available.

Scheduled scaling actions combined with a diverse set of instances under the capacity-optimized strategy ensure higher resilience and better timing for instance launches.

This approach directly supports the Resiliency design principle in the AWS Well-Architected Framework.

???? References:

Best Practices for EC2 Spot Instances

Capacity-Optimized Allocation Strategy

Amazon RDS Custom for Oracle: This service allows you to bring your own Oracle Database licenses and provides the flexibility to customize the database settings, making it suitable for applications that require privileged access and third-party database features.

BYOL (Bring Your Own License):

RDS Custom supports the BYOL model, allowing you to use your existing Oracle licenses and comply with licensing requirements.

This helps in leveraging existing investments and reducing migration costs.

Customization and Third-Party Features:

RDS Custom allows for deeper customization of the database environment compared to standard RDS instances.

This makes it possible to support the third-party features that your application relies on without significant changes.

Migration Process:

Use native Oracle tools like Data Pump or RMAN to migrate the database to RDS Custom.

Customize the database settings post-migration to ensure compatibility with third-party features.

Why Option D is Correct:

IAM Roles with Instance Profiles: Allow applications to access AWS services securely without hardcoding long-term access keys.

Short-Term Credentials: IAM roles issue short-term credentials dynamically managed by AWS.

Why Other Options Are Not Ideal:

Option A and B: Embedding or retrieving long-term access keys introduces security risks and operational overhead.

Option C: Combining IAM roles with Parameter Store adds unnecessary complexity.

AWS References:

IAM Roles and Instance Profiles:AWS Documentation - IAM Roles

AWS App2Container is a command-line tool that helps containerize existing Java and .NET applications running on-premises or on virtual machines, with minimal refactoring. By using Amazon EKS, the company benefits from a managed Kubernetes service, which significantly reduces the operational overhead compared to managing Kubernetes on EC2.

Amazon RDS for SQL Server provides a fully managed SQL Server database engine with automated backups, patching, and high availability through Multi-AZ deployments. This eliminates the need for the company to manage database infrastructure and software manually.

Overall, option A provides the most streamlined and managed approach for both the application and database layers with the least operational effort.

IAM Roles for Service Accounts (IRSA): IRSA allows you to associate an IAM role with a Kubernetes service account. This enables pods to assume the IAM role and access AWS resources securely.

Annotating Service Accounts: By annotating Kubernetes service accounts with the ARN of the IAM role, you establish the association required for IRSA.

OIDC Identity Provider: EKS clusters use OpenID Connect (OIDC) to authenticate service accounts. Setting up a trust relationship between the IAM role and the OIDC provider allows the Kubernetes service account to assume the IAM role.

The requirement is to restrict actions by Region to prevent accidental cross-Region operations that could violate data residency rules. The most direct and flexible way to enforce Region-based restrictions in AWS is to use IAM condition keys, specifically aws:RequestedRegion, in identity-based policies (and commonly in permission boundaries or SCPs when managing an organization).

Option B is correct because it applies Region constraints at authorization time. By adding conditions that allow actions only when aws:RequestedRegion matches an approved list (or denies when it matches disallowed Regions), the company can prevent users and roles from creating, modifying, or accessing resources in the wrong Region. This approach is broad and can be applied across many services, not just EC2, making it suitable for enforcing data residency boundaries across a multi-Region footprint.

Option A is too narrow because it restricts only ec2:RunInstances. Data residency concerns typically apply to many services (S3, RDS, DynamoDB, KMS, etc.), and limiting only EC2 does not prevent accidental data operations elsewhere. Option C controls where requests come from (source IP), not which Region is targeted. Option D (AWS Config) is detective, not preventative; it can alert after noncompliant actions occur, which does not meet the requirement to prevent accidental operations.

Therefore, B best meets the requirement by enforcing Region-level guardrails through IAM authorization conditions, helping ensure workloads remain within approved geographic boundaries.

Amazon Kinesis Data Streams in on-demand mode is purpose-built for real-time ingestion of streaming data and scales automatically with traffic, which is ideal for fluctuating workloads like clickstream data.

Combined with AWS Lambda, which scales concurrently based on incoming events, this setup ensures efficient, real-time processing with minimal configuration and cost overhead.

Option B involves Firehose, which is not optimal for low-latency processing. Option C is incorrect as Kinesis Video Streams is designed for video data, not clickstream. Option D introduces Flink, which adds unnecessary complexity when Lambda suffices.

Amazon FSx for Lustre is a high-performance file system optimized for fast processing of workloads such as machine learning, high-performance computing (HPC), and video processing. It integrates natively with Amazon S3, allowing you to:

Access S3 Data: FSx for Lustre can be linked to an S3 bucket, presenting S3 objects as files in the file system.

High Performance: It provides sub-millisecond latencies, high throughput, and millions of IOPS, which are ideal for ML workloads.Amazon Web Services, Inc.

Minimal Operational Overhead: Being a fully managed service, it reduces the complexity of setting up and managing high-performance file systems.

To optimize costs for long-term data storage, AWS recommends using S3 Lifecycle policies to automate transitions across storage classes and ultimately expire old data.

S3 Standard-IA is suited for data that is accessed less frequently but requires millisecond retrieval times. It is ideal for 6-month-old data still used in monthly reports.

S3 Glacier Deep Archive is the lowest-cost option, designed for data accessed once or twice a year, such as regulatory audits — perfect for 2+ year-old data.

Lifecycle expiration rules allow S3 to automatically delete objects older than 7 years, aligning with the business retention policy.

These transitions are cost-effective and fully automated, aligning with the Cost Optimization pillar in the AWS Well-Architected Framework.

???? Reference:

S3 Storage Class Comparison

Lifecycle Management

For the migration of data from an on-premises Oracle database to Amazon Aurora PostgreSQL, this solution effectively handles schema conversion, data migration, and ongoing data replication.

AWS Schema Conversion Tool (SCT): SCT is used to convert the Oracle database schema to a format compatible with Aurora PostgreSQL. This tool automatically converts the database schema and code objects, like stored procedures, to the target database engine.

AWS Database Migration Service (DMS): DMS is employed to perform the data migration. It supports both full-load migrations (for initial data transfer) and continuous replication of ongoing changes (Change Data Capture, or CDC). This ensures that any updates to the Oracle database during the migration are captured and applied to the Aurora PostgreSQL database, minimizing downtime.

Why Not Other Options?:

Option A (SCT + DMS full-load only): This option does not capture ongoing changes, which is crucial for a live database migration to ensure data consistency.

Option B (DataSync + S3): AWS DataSync is more suited for file transfers rather than database migrations, and it doesn’t support ongoing change replication.

Option D (Snowball + S3): Snowball is typically used for large-scale data transfers that don’t require continuous synchronization, making it less suitable for this scenario where ongoing changes must be captured.

AWS References:

AWS Schema Conversion Tool- Guidance on using SCT for database schema conversions.

AWS Database Migration Service- Detailed documentation on using DMS for data migrations and ongoing replication.

The correct solution is to create anIAM roleand attach it to the EC2 instance profile. AWS documentation states that applications running on EC2 should use IAM roles so the instance can receivetemporary credentials automaticallythrough the instance metadata service. This avoids embedding long-term access keys in code or on the server. DynamoDB supports IAM and temporary credentials, so the application can use the role’s permissions to access the table securely. EC2 key pairs are only for SSH access and have nothing to do with DynamoDB authorization. IAM users and long-term access keys are less secure and create unnecessary credential management overhead.

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AWS Global Accelerator provides static anycast IP addresses that remain constant regardless of Regional failover. AWS directs traffic to the optimal healthy Region without relying on DNS TTL values, eliminating the risk of stale DNS caches.

Route 53 routing (Options B and D) still depends on DNS caching behavior. CloudFront (Option A) is for content delivery, not Regional failover for applications.

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Pre-Signed URLs: Allow temporary access to S3 buckets, making it easy to manage time-limited upload permissions without complex operational overhead.

Lambda for Automation: Automatically generates and provides pre-signed URLs when users authenticate, minimizing manual steps and code complexity.

Least Operational Overhead: Requires no custom authentication service or deep integration with STS or Cognito.

Amazon S3 Pre-Signed URLs Documentation

To break down consolidated billing costs by “product line” using tags, the company must use cost allocation tags and ensure those tags are activated for billing at the payer/management level. Because the teams have already applied user-defined tags to the compute resources across accounts, the correct approach is to (1) use those user-defined tags in the billing tools and (2) activate them so they appear in cost and usage reporting for consolidated billing.

B is required because cost reporting by product line depends on selecting the user-defined cost allocation tag key (for example, ProductLine=...) in AWS billing and cost management tooling (such as Cost Explorer reports). AWS-generated tags are not what teams typically use for chargeback by business dimension, and the scenario explicitly says teams tagged resources (i.e., user-defined).

E is required because in an AWS Organizations consolidated billing setup, cost allocation tag activation is handled centrally from the Organizations management account so that the tags can be used consistently in consolidated cost views and reporting. Activating tags centrally ensures the billing system recognizes and includes those tag dimensions in cost allocation data.

Option C is not relevant to billing breakdown; Resource Groups is for organizing and operating on resources, not for consolidated billing allocation. Option D is unnecessary in this scenario’s intended best practice because activation for consolidated billing reporting is done from the management account to standardize reporting. In short, you tag resources (already done), then activate the tag for billing and use it in billing reports to see cost by product line across accounts and Regions.

Therefore, B and E together meet the requirement with the correct billing-focused steps.

AWS Lambda is not suitable for long-running jobs that can take up to 20 minutes, as Lambda has a maximum execution duration of 15 minutes.

Amazon ECS with AWS Fargate allows you to run containers without managing EC2 instances, providing a scalable and highly available environment. You can scale Fargate tasks to handle large and parallel video processing jobs. Amazon Aurora is a highly available, managed relational database. S3 Intelligent-Tiering is cost-effective for storing large video files with variable access patterns.

AWS Documentation Extract:

" AWS Fargate lets you run containers without managing servers or clusters, providing a highly available and scalable compute environment. Fargate is suitable for running data processing workloads that require long-running compute tasks. "

(Source: AWS Fargate documentation, Use Cases)

A: Lambda is not suitable for long-running (over 15 min) or heavy compute jobs.

C: Amazon EMR is optimized for big data analytics, not specific video processing. FSx for Lustre and Kinesis are not best fit for this use case.

D: EKS with EC2 adds operational overhead and RDS in a single AZ is not highly available; Glacier Deep Archive is not suitable for frequently accessed video files.

End-to-end encryption means TLS is used not only from the client to the ALB, but also from the ALB to the EC2 targets. The least operational effort is achieved by using AWS Certificate Manager (ACM) Amazon-issued certificates where possible, because ACM automates key management, certificate provisioning, and renewal for supported use cases. Associating an ACM certificate with the ALB is a standard managed approach for TLS termination at the load balancer, and using managed certificates reduces the overhead of tracking expiration, renewing, and distributing certificates.

For encryption on the backend connection (ALB to instances), the instances must present a certificate and complete TLS. Using Amazon-issued ACM certificates (via supported mechanisms) reduces manual certificate lifecycle work compared with importing and managing third-party certificates. By avoiding third-party cert procurement and manual renewals, the solution minimizes ongoing operations and reduces the risk of outages due to expired certificates. This aligns with the requirement for the least operational effort while meeting the security requirement.

Option A is far more operationally heavy: CloudHSM is intended for scenarios requiring customer-managed HSMs and adds complexity in deployment, scaling, integration, and operations. Option B introduces self-signed certificates on instances, which increases operational friction (distribution, trust, rotation) and is not as clean for managed operations. Option C works but requires managing third-party certificate lifecycle (renewals, re-import, redeploy to instances), which is more overhead than Amazon-issued managed certificates.

Therefore, D best meets end-to-end encryption needs with the lowest ongoing operational burden by using AWS-managed certificate issuance and lifecycle management capabilities.

AWS Shield Advanced is designed to provide enhanced protection against DDoS attacks with proactive engagement and response capabilities, making it the best solution for this scenario.

AWS Shield Advanced: This service provides advanced protection against DDoS attacks. It includes detailed attack diagnostics, 24/7 access to the AWS DDoS Response Team (DRT), and financial protection against DDoS-related scaling charges. Shield Advanced also integrates with Route 53 and the Application Load Balancer (ALB) to ensure comprehensive protection for your web applications.

Route 53 and ALB Protection: By adding your Route 53 hosted zones and ALB resources to AWS Shield Advanced, you ensure that these components are covered under the enhanced protection plan. Shield Advanced actively monitors traffic and provides real-time attack mitigation, minimizing the impact of DDoS attacks on your application.

Why Not Other Options?:

Option A (AWS Config): AWS Config is a configuration management service and does not provide DDoS protection or detection capabilities.

Option B (AWS WAF): While AWS WAF can help mitigate some types of attacks, it does not provide the comprehensive DDoS protection and proactive engagement offered by Shield Advanced.

Option C (GuardDuty): GuardDuty is a threat detection service that identifies potentially malicious activity within your AWS environment, but it is not specifically designed to provide DDoS protection.

AWS References:

AWS Shield Advanced- Overview of AWS Shield Advanced and its DDoS protection capabilities.

Integrating AWS Shield Advanced with Route 53 and ALB- Detailed guidance on how to protect Route 53 and ALB with AWS Shield Advanced.

Creating a manual copy of the automated snapshot is the most operationally efficient option because it directly meets the requirement—retain a specific snapshot beyond the automated retention window—with the least added process and tooling. In Amazon RDS, automated backups and their snapshots are retained only for the configured backup retention period (up to the service maximum). When that retention period is exceeded, older automated snapshots are removed automatically. However, manual snapshots are retained until you explicitly delete them, so converting (copying) an automated snapshot to a manual snapshot is the standard operational approach to keep a point-in-time backup for long-term retention.

Option C is incorrect because you cannot extend automated snapshot retention beyond the maximum supported retention; also, setting “45 days” may still be within or beyond the service limits depending on the engine and configuration, and it doesn’t guarantee indefinite retention. Option B (export to S3) is not the most operationally efficient for the stated goal: exporting is a different workflow (often used for analytics, archiving in open formats, or cross-tool usage) and introduces extra steps, format considerations, and ongoing management in S3. Option D is also heavier operationally: native SQL Server backups require managing backup jobs, storage layout, restores, and permissions, and it shifts responsibility to the customer for operational correctness.

Therefore, A is the simplest and most AWS-native way to preserve an RDS snapshot long-term with minimal operational overhead.

AWS Firewall Manager integrates with AWS Organizations to centrally manage and apply security group policies, AWS WAF rules, and AWS Shield Advanced protections. It automates the propagation of rules across accounts and Regions and can also audit and remediate noncompliant configurations.

Aservice control policyattached at the organization root is the right preventive control because SCPs define the maximum permissions for principals in member accounts across the organization. AWS documentation states that SCPs restrict permissions for IAM users and roles in member accounts and that an explicit deny overrides allows from other policies. That makes an SCP the cleanest centralized way to block creation of IAM users and access keys everywhere. Inline user policies would be harder to maintain, and GuardDuty or Config would be detective or corrective controls rather than the preventive control the question asks for.

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This question focuses on scalability, operational overhead, and performance during unpredictable workloads.

API Gateway + AWS Lambda enables serverless compute, which scales automatically based on the number of requests. It requires no provisioning, maintenance, or patching of servers — eliminating operational overhead.

Amazon DynamoDB is a fully managed NoSQL database optimized for high-throughput workloads with single-digit millisecond latency.

Amazon S3 is designed for high availability and durability, and is ideal for storing unstructured content such as user-uploaded images.

By leveraging these fully managed and scalable services, the architecture meets the requirement of supporting rapid user growth while minimizing operational complexity. This solution aligns with the Performance Efficiency and Operational Excellence pillars in the AWS Well-Architected Framework.

???? References:

Serverless Web Application Architecture

Using DynamoDB with Lambda

Best Practices for API Gateway

Amazon EBS Snapshots Recycle Bin enables you to specify retention rules for EBS snapshots based on tags. When snapshots are deleted, they are retained in the Recycle Bin for a specified duration, preventing accidental deletion. Tag-level rules allow selective protection without changing IAM roles or user permissions.

To decouple distributed workloads and improve scalability and resiliency, Amazon SQS should be used as a reliable job queue. The compute nodes (workers) can poll the SQS queue for tasks, and EC2 Auto Scaling can dynamically scale instances based on the ApproximateNumberOfMessages metric.

From AWS Documentation:

“Amazon SQS enables you to decouple application components, allowing each part to scale independently. You can scale EC2 instances automatically based on the number of messages in the queue.”

(Source: Amazon SQS Developer Guide – Scaling Consumers with Auto Scaling)

Why B is correct:

Eliminates the single point of failure (the primary coordinator).

Enables event-driven scaling based on queue depth.

Provides durability and resiliency since messages are stored redundantly.

Fully managed and integrates seamlessly with Auto Scaling policies.

Why other options are incorrect:

A: Scheduled scaling does not respond to variable workloads.

C & D: Misuse of CloudTrail/EventBridge; not intended for workload coordination.

EC2 Auto Scaling warm pools allow you to pre-initialize instances, reducing the delay in scale-out events. This results in significantly faster response times during demand surges while remaining cost-effective compared to always running at peak capacity.

Amazon S3 is suitable for storing data that needs to be accessed weekly and integrates with AWS Key Management Service (KMS) to provide encryption at rest with server-side encryption using KMS-managed keys (SSE-KMS).

SSE-KMS uses envelope encryption and allows automatic key rotation and logging through AWS CloudTrail, satisfying the requirements for audit trails and compliance.

S3 Glacier Deep Archive is unsuitable due to its high retrieval latency. SSE-C requires customer-side management of encryption keys, with no support for automatic rotation or audit. SSE-S3 does not use customer-managed keys and lacks fine-grained control and auditing.

The requirement is to monitor network metrics such as total packet loss and round-trip time (RTT) between on-premises and AWS over Site-to-Site VPN with minimal operational overhead. AWS CloudWatch Network Monitor (formerly known as VPC Network Manager) provides a managed solution to monitor connectivity, including packet loss and latency, between AWS and on-premises networks. This solution does not require managing any additional infrastructure like EC2 instances or Lambda functions and thus reduces operational overhead significantly.

CloudWatch Network Monitor leverages AWS-managed probes and integrates natively with CloudWatch dashboards and alarms, enabling automated, centralized monitoring of network health. This aligns with the AWS Well-Architected Framework’s operational excellence pillar by minimizing manual intervention and enabling proactive detection of network issues.

Option B, C, and D involve creating custom probes with EC2, Lambda, or Batch jobs, which increases complexity, cost, and maintenance effort. They also require scheduling, script management, and additional monitoring infrastructure.

The correct answer isDbecause the company needs to authenticate users from anon-premises LDAP directoryto theAWS Management Console, but the directory isnot SAML-compatible. In this scenario, the AWS-recommended pattern is to use acustom identity brokerthat authenticates users against the existing LDAP directory and then requeststemporary AWS credentialsfromAWS Security Token Service (AWS STS). This enables federated access to AWS without creating long-term IAM user credentials for each person.

A custom identity broker serves as the intermediary between the non-SAML directory and AWS. After validating a user with LDAP, the broker can call AWS STS to issue short-lived credentials or console sign-in access. This approach preserves the use of the company’s existing identity source while meeting AWS security best practices for temporary credentials and centralized identity management.

Option A is incorrect becauseAWS IAM Identity Centertypically relies on supported identity sources and federation methods, and the question explicitly states that the LDAP directory is not SAML-compatible. Option B is incorrect because IAM policies do not integrate directly into LDAP as an authentication mechanism. Option C is incorrect because rotating IAM credentials tied to LDAP changes still relies on long-term credentials and does not provide a proper federated sign-in model.

AWS federation guidance supports the use of acustom identity brokerwhen an organization has a non-SAML-compatible identity system. Therefore, the best solution is to develop anon-premises custom identity brokerthat usesAWS STSto obtain short-lived credentials for AWS Management Console access.

Key Requirements:

High availability and automatic recovery.

Separate transactional and analytical queries with minimal performance impact.

Allow up to a 4-hour lag for analytical queries.

Analysis of Options:

Option A:

Multi-AZ deployments provide high availability but do not include read replicas for separating transactional and analytical queries.

Analytical queries on the secondary DB instance would impact the transactional workload.

Incorrect Approach:Does not meet the requirement of query separation.

Option B:

Multi-AZ DB clusters provide high availability and include a reader endpoint. However, these are better suited for Aurora and not RDS for MySQL.

Incorrect Approach:Not applicable to standard RDS for MySQL.

Option C:

Multiple read replicas allow separation of transactional and analytical workloads.

Queries can be pointed to a replica in a different AZ, ensuring no impact on transactional queries.

Correct Approach:Meets all requirements with high availability and query separation.

Option D:

Creating nightly snapshots and read-only databases adds significant operational overhead and does not support the 4-hour lag requirement.

Incorrect Approach:Not practical for dynamic query separation.

AWS Solution Architect References:

Amazon RDS Read Replicas

Multi-AZ Deployments

Amazon S3 is designed for durability, scalability, and millisecond access. For small monthly data volumes (300 MB), S3 Standard is cost-effective and provides immediate access. To meet 30-day retention, Lifecycle policies can automatically expire objects after the required time. For disaster recovery, S3 Cross-Region Replication (CRR) copies objects across Regions to a backup bucket, ensuring data resiliency. OpenSearch (A) is not needed because the requirement is storage and retrieval, not indexing. Aurora or RDS options (C, D) add unnecessary complexity and cost, as a relational database is not required for JSON storage and millisecond retrieval. Therefore, option B provides the simplest, most resilient, and cost-optimized solution.

For maximum resiliency and fault tolerance in a mission-critical scenario, AWS recommends redundant Direct Connect connections from multiple data centers to multiple AWS Direct Connect locations.

This protects against:

Data center failure

Device failure

Location outages

“For workloads that require high availability, we recommend that you use multiple Direct Connect connections at multiple Direct Connect locations.”

— AWS Direct Connect Resiliency Recommendations

Option C follows AWS maximum resiliency model.

Amazon FSx for ONTAP supports both NFS and SMB protocols and includes automated tiering between SSD and capacity pool storage, optimizing cost and performance. It is ideal for mixed operating systems and varied access patterns with minimal administrative overhead.

AWS Lambda is not a good fit here because AWS documents that a standard Lambda invocation can run forup to 15 minutes, while this workload can takeup to 30 minutes. That makes the Lambda-based answers unsuitable. AnSQS standard queueis a good match for decoupling uploads from processing and for allowing multiple jobs to run in parallel. Running the processors onAmazon ECS with AWS Fargateminimizes operational overhead because the company does not have to manage EC2 hosts. ECS service scaling can also be driven from queue-backed metrics, allowing the processing fleet to expand as the queue grows. Therefore, S3 notifications to SQS with Fargate-based processing is the most appropriate low-overhead design.

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This solution directly addresses the scalability and high availability requirements with minimal downtime.

Additional Reader Instances: Adding more reader instances to the Aurora cluster will distribute the read load, improving the performance of the application under heavy read traffic. Aurora reader instances automatically replicate the data from the writer instance, enabling you to scale out read operations.

Amazon RDS Proxy: RDS Proxy improves database availability by managing database connections more efficiently and providing a connection pool. This reduces the overhead on the Aurora cluster during peak loads, further enhancing performance and availability without requiring changes to the application code.

Why Not Other Options?:

Option A (EventBridge and Lambda): This doesn’t directly address the performance and availability issues. Logging state changes and adding reader nodes on failure events doesn’t provide proactive scalability.

Option B (Zero-Downtime Restart and Activity Streams): Zero-Downtime Restart (ZDR) is useful for minimizing downtime during maintenance but doesn’t directly improve scalability. Database Activity Streams are more for security monitoring than for performance enhancement.

Option D (ElastiCache for Redis): While adding a caching layer can help with read performance, it introduces complexity and may not be necessary if additional reader instances can handle the load.

AWS References:

Amazon Aurora Scaling- Information on scaling Aurora clusters with reader instances.

Amazon RDS Proxy- Details on how RDS Proxy can improve database performance and availability.

This solution is designed to provide high availability and low-latency access to block storage across multiple Availability Zones with minimal implementation effort.

Windows Server Cluster Across AZs: Configuring a Windows Server Failover Cluster (WSFC) that spans two Availability Zones ensures that the application can failover from one instance to another in case of a failure, meeting the high availability requirement.

Amazon FSx for Windows File Server: FSx for Windows File Server provides fully managed Windows file storage that is accessible via the SMB protocol, which is suitable for Windows-based applications. It offers high availability and can be used as shared storage between the cluster nodes, ensuring that both nodes have access to the same data with low latency.

Why Not Other Options?:

Option B (EBS with application-level replication): This requires complex configuration and management, as EBS volumes cannot be directly shared across AZs. Application-level replication is more complex and prone to errors.

Option C (FSx for NetApp ONTAP with iSCSI): While this is a viable option, it introduces additional complexity with iSCSI and requires more specialized knowledge for setup and management.

Option D (EBS with EBS-level replication): EBS-level replication is not natively supported across AZs, and setting up a custom replication solution would increase the implementation effort.

AWS References:

Amazon FSx for Windows File Server- Overview and benefits of using FSx for Windows File Server.

Windows Server Failover Clustering on AWS- Guide on setting up a Windows Server cluster on AWS.

The best design is to place an internet-facing Application Load Balancer in public subnets and place the EC2 instances in private subnets with no direct internet access. This keeps the application reachable from the internet while preventing direct internet connectivity to the instances. Because the clients use HTTP, an ALB is more appropriate than an NLB because ALB operates at Layer 7 and supports HTTP routing, health checks, host-based routing, and path-based routing. The EC2 instances should be part of an Auto Scaling group so that the application can scale based on traffic demand. Options that place the instances in public subnets violate the security requirement. The NLB options are less suitable for HTTP application-layer routing.

AWS Batch supports Windows-based jobs and automates provisioning and scaling of compute environments. Paired with AWS Fargate, it removes the need to manage infrastructure. This solution requires the least operational overhead and is cloud-native, providing flexibility and scalability.

Amazon QuickSight includes built-in ML-powered forecasting capabilities, allowing you to create, visualize, and interact with time series forecasts directly within the BI dashboard, with no ML experience or infrastructure management required. This is the lowest management overhead solution.

AWS Documentation Extract:

" Amazon QuickSight provides built-in ML-powered forecasting, allowing business users to forecast future trends with a few clicks and no machine learning expertise required. "

(Source: Amazon QuickSight documentation)

A, C, D: Require additional setup, management, or ML knowledge.

AWS documentation states that EC2 Auto Scaling is the recommended, cost-effective, and fault-tolerant method to manage workloads with predictable or varying demand. Auto Scaling automatically adds instances during peak traffic and terminates them when demand is low, reducing compute cost while maintaining availability across multiple Availability Zones.

Reserved Instances (Option B) would force the company to pay for peak capacity all day, which is not cost-effective.

Stopping instances manually (Option C) or vertically scaling instances (Option D) reduces fault tolerance and increases operational overhead.

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The correct answer isDbecause the application is written entirely inJavaScript and runs in users’ web browsers, which means the workload is essentially astatic web application. Static assets such as HTML, JavaScript, CSS, and related files are best hosted onAmazon S3, which provides highly durable and low-cost object storage. PuttingAmazon CloudFrontin front of the S3 bucket allows the application to be delivered globally through edge locations, which reduces latency for users in many countries while also lowering the load on the origin.

This design is more cost-effective than continuing to serve the application from EC2 instances behind an ALB because it eliminates most of the compute and load balancing cost for static content delivery. CloudFront caches the content close to users and can improve performance worldwide without the complexity of deploying full application stacks in multiple Regions.

Option A is less cost-effective because it still depends on the ALB and EC2 instances as the origin for content that is static. Also, CloudFront requires an ACM certificate inus-east-1for custom domain names, so reusing the existing certificate from the ALB is not the right assumption. Option B introduces significant multi-Region infrastructure cost and management overhead. Option C is unnecessarily complex because multiple S3 buckets in multiple Regions are not required when CloudFront can cache globally from a single origin.

AWS best practices for static web applications recommendAmazon S3 for storageandAmazon CloudFront for global distribution. This approach provides strong performance, simplicity, and cost optimization.

This is a classic session-persistence problem. AWS Elastic Load Balancing documentation explains thatstickinesslets a load balancer bind a user’s session to a specific target. For an ALB,application-based cookie stickinesscan be enabled at the target group level, which is useful when the application expects a user to continue hitting the same backend instance for the duration of a session. That prevents users from being redirected back to login because of requests landing on different instances. The other options either do not solve the session problem or reduce availability by forcing traffic to one instance. (docs.aws.amazon.com)

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Amazon S3 Object Lambda allows you to add your own code to process data retrieved from S3 before it is returned to an application. You can use this to dynamically redact or remove PII for specific applications on-the-fly, eliminating the need to manage multiple buckets or datasets, thus minimizing operational overhead.

Reference Extract:

" S3 Object Lambda enables you to process and transform data as it is retrieved from S3, supporting use cases such as redacting sensitive information before returning data to an application. "

Source: AWS Certified Solutions Architect – Official Study Guide, Data Security and Transformation section.

The combination of these solutions provides an efficient and automated way to migrate data while preserving metadata and ensuring cleanup:

Create a new S3 bucket with versioning enabled(Option A) to preserve object metadata like version IDs during migration.

UseS3 batch operations(Option B) to efficiently copy data from specific prefixes in the source bucket to the destination bucket, ensuring minimal overhead.

Use an S3 Lifecycle policy(Option F) to automatically delete the data from the source bucket after it has been migrated, reducing manual intervention.

Option C (CopyObject API): This approach would require more manual scripting and effort.

Option D (Same-Region Replication): SRR is designed for ongoing replication, not for one-time migrations.

Option E (DataSync): DataSync adds more complexity than necessary for this task.

AWS References:

S3 Batch Operations

S3 Lifecycle Policies

To meet the requirements, the key must support automatic rotation, and the company must be able to disable (deactivate) the key and schedule deletion. In AWS KMS, these lifecycle controls are available for customer managed keys. Automatic key rotation is supported for symmetric customer managed KMS keys used for encryption and decryption operations. When automatic rotation is enabled, AWS KMS generates new cryptographic material for the key on a regular schedule while the key ID remains the same, helping organizations meet compliance and security best practices without manual operational work.

Option C is the only choice that explicitly combines a symmetric customer managed key with automatic rotation enabled, which directly satisfies the rotation requirement. As a customer managed key, it can also be disabled (to prevent use) and scheduled for deletion (with a waiting period), meeting the rest of the lifecycle needs.

Option A is incorrect because automatic rotation is not generally available for asymmetric KMS keys in the same way; asymmetric keys are used for specialized use cases such as signing or asymmetric encryption, and rotation behavior differs. Options B and D mention “disabling envelope encryption,” which is not a configurable “option” you turn off in KMS; envelope encryption is a recommended pattern where KMS protects data keys, and services commonly use it under the hood. Those options therefore do not describe a valid configuration that meets the requirement.

Therefore, the correct solution is to create a symmetric customer managed KMS key and enable automatic rotation, while using standard KMS controls to disable and schedule deletion when required.

To achieve a 60-second RTO, pre-warming the DR environment (including running EC2 instances and Route 53 health checks) is essential. Active/passive failover using Route 53 with health checks ensures fast redirection when the primary Region becomes unavailable. S3 cross-region replication ensures document availability.

AWS Storage Gateway Tape Gateway provides a seamless way to migrate backup data to AWS without requiring changes to the backup software. Migrating to S3 Glacier Deep Archive ensures long-term, cost-effective storage for data that rarely needs retrieval.

Option A:S3 Standard-IA is more expensive than Glacier for long-term storage.

Option B and D:Glacier Flexible Retrieval is costlier than Glacier Deep Archive for archival use cases with low retrieval frequency.

AWS Documentation References:

AWS Storage Gateway Tape Gateway

S3 Glacier Storage Classes

ElastiCache for Redis OSS supportsMulti-AZ with automatic failover, which is exactly the feature required here. AWS documentation states that when Multi-AZ is enabled and the primary node fails, ElastiCache automatically promotes a read replica to primary, minimizing downtime and restoring write capability without requiring manual promotion steps. Backups are useful for recovery, but they do not provide automatic operational failover. A design that depends on manual promotion is also weaker than native automatic failover. Since the question explicitly asks for a solution that canautomatically fail over, the correct answer is to enableMulti-AZfor the replication group.

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To capture DNS query and response data, including response codes, Amazon Route 53 provides query logging, which is the most precise and AWS-supported solution for this requirement.

Option A enables Route 53 query logging, which records detailed information about DNS queries, such as the queried domain, record type, source IP, and DNS response code. These logs are delivered to Amazon CloudWatch Logs, where administrators can search, analyze, and retain them for forensic investigation and root cause analysis.

Option B is incorrect because AWS CloudTrail records API calls to AWS services, not DNS query traffic. Option C provides aggregated metrics (such as query counts and health checks) but does not include per-query response codes. Option D offers best-practice recommendations but does not collect or analyze DNS query data.

Therefore, A is the correct solution because Route 53 query logging provides the detailed, low-level DNS visibility required for troubleshooting and operational analysis.

Amazon SQS with Amazon ECS on AWS Fargate is the best managed architecture for containerized, loosely coupled message processing. SQS is a fully managed message queue that decouples distributed application components and scales without the operational burden of managing broker infrastructure. SNS can fan out messages to the SQS queue when publish-subscribe behavior is needed. ECS on Fargate runs containers without requiring the company to manage EC2 instances, Kubernetes worker nodes, or server capacity. Amazon MQ is useful when applications need traditional broker compatibility, but it does not provide the same virtually unlimited scaling model as SQS standard queues. EC2 Reserved Instances also violate the goal of fully managed infrastructure.

Securing the root user account requires setting a strong password and enabling multi-factor authentication (MFA). AWS recommends never sharing the root user credentials, setting up individual IAM users for everyday operations, and always protecting the root user with MFA for maximum security.

Reference Extract:

" AWS recommends securing the root user with a strong password and enabling multi-factor authentication (MFA). Do not use or share root credentials for everyday tasks. "

Source: AWS Certified Solutions Architect – Official Study Guide, IAM and Security Best Practices section.

Option A: Importing customer-managed keys into AWS KMS ensures that encryption key material remains under the company’s control.

Option D: S3 Glacier with server-side encryption using customer-provided keys (SSE-C) complies with the need for controlled encryption and provides cost-effective storage for backups.

AWS Key Management Service Importing Keys Documentation,S3 Encryption Documentation

AWS DataSync provides a fully managed, secure, and high-performance service for transferring large amounts of data between on-premises storage and Amazon S3. It uses TLS encryption in transit and automates data validation, scheduling, and monitoring.

From AWS Documentation:

“AWS DataSync securely and efficiently transfers large amounts of data online between on-premises storage and AWS services. All data is encrypted in transit using TLS.”

(Source: AWS DataSync User Guide – How DataSync Works)

Why B is correct:

Encrypts all data in transit automatically.

Optimized for high-throughput WAN environments (100 Mbps to multi-Gbps).

Fully managed, with no need to provision additional infrastructure.

Integrates natively with S3 and supports incremental syncs.

Why others are incorrect:

A: DMS is designed for database migration, not unstructured data.

C: Snowball is for offline migrations, not needed given available connectivity.

D: Direct Connect is costly for temporary data transfers and unnecessary here.

The most secure option is to use across-account IAM rolein the central logging account and allow authorized Lambda functions in member accounts to assume that role. AWS cross-account access guidance is based on trusted roles rather than sharing long-term IAM user credentials. This keeps access temporary, auditable, and centrally controlled. The IAM user answers are weaker because they depend on long-term credentials, which is not the recommended pattern for Lambda-based cross-account access. A bucket policy that broadly allows “AWS Lambda” is also too permissive and not scoped to the organization’s trusted workloads. Therefore, a central role with an appropriate trust policy is the strongest design among the listed choices.

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The most cost-effective general solution isDynamoDB auto scaling. AWS recommends atarget utilization of 70%for provisioned throughput with auto scaling, which lets DynamoDB adjust capacity up or down based on sustained workload patterns. That improves both read and write performance while controlling cost better than manual scaling. A GSI is only useful for specific alternate query patterns and does not solve overall throughput management by itself. DAX helps only with read-heavy caching, not writes. A custom CloudWatch-plus-Lambda scaling solution adds unnecessary operational work compared to native auto scaling. Because the question asks broadly for read and write performance at the best cost, auto scaling with the recommended 70% target is the strongest answer.

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The workload is Windows-based and requires a shared file system with SMB support and very high throughput for 4K video editing.

Amazon FSx for Windows File Server is a fully managed, highly available native Windows file system that supports the SMB protocol, Active Directory integration, and can deliver high throughput and low latency suitable for media workloads.

FSx for Windows File Server supports automatic storage scaling to grow file system capacity as data increases, matching the requirement of +1 TB per week with minimal admin effort.

A Multi-AZ SSD deployment provides high availability and performance.

Why others are not correct:

B: Amazon EFS is NFS, not SMB, and is optimized for Linux clients, not Windows-based environments.

C: FSx for Lustre is a high-performance POSIX file system typically used with Linux-based HPC workloads, not Windows + SMB.

D: S3 File Gateway is not designed for sustained multi-GB/s shared-edit performance and adds additional complexity; it is more suited for backup/archival and limited shared file access.

Amazon EFS allows automatic transitions to Infrequent Access (IA) and back to Standard when accessed again using the lifecycle policy.

By specifying the bursting throughput mode, throughput scales automatically with file system size.

“With EFS Lifecycle Management, you can automatically move files to EFS Infrequent Access storage and automatically return them to Standard storage when accessed.”

“The Bursting Throughput mode scales with your file system size.”

— Amazon EFS Lifecycle Management

This option matches all requirements:

Auto transition to IA after 30 days.

Auto transition back to Standard on access.

Bursting throughput for scaling with file system size.

The correct answer isBbecause the requirement explicitly calls for awrite once, read many (WORM)approach and a mandatory retention period of1 year.Amazon S3 Object Lock in compliance modeis the AWS feature designed specifically for this purpose. It prevents objects from being deleted or overwritten for a fixed retention period, even by privileged users. That directly satisfies the need to preserve confidential medical results for at least one year after creation.

Usingcompliance modeis important because it enforces retention in a way that cannot be bypassed by users or administrators. This is appropriate for regulated workloads such as medical records, where strong immutability controls are required. The company can then useIAM policiesto allow only a small set of approved users to upload new files while granting other authorized users read-only access.

Option A is incorrect becauseMFA Deletehelps protect against accidental deletion, but it does not provide a full WORM retention model and does not prevent overwrites in the same way as Object Lock. Option C is not sufficient because IAM and bucket policies can be changed by administrators with enough permissions and therefore do not provide the same immutable retention guarantee. Option D is overly complex and does not enforce WORM behavior; tracking object hashes only detects changes after the fact.

AWS best practices for immutable retention on S3 recommendS3 Object Lockwhen legal hold or retention requirements exist. For least implementation effort and proper WORM enforcement,S3 Object Lock in compliance modeis the most appropriate solution.

For steady, predictable EC2 usage with potential changes in instance families over time, AWS recommends Savings Plans. Compute Savings Plans “apply to any EC2 instance regardless of region, instance family, operating system, or tenancy,” and also apply to AWS Fargate and AWS Lambda, delivering the most flexibility over a multi-year horizon. A 3-year term provides the highest discount among Savings Plans for long-lived workloads. EC2 Instance Savings Plans are limited to a chosen instance family in a region; as needs evolve (e.g., size or family changes), discounts may not fully apply. Spot Instances are not appropriate for long, interruption-sensitive jobs because Spot capacity can be reclaimed with short notice. Therefore, a Compute Savings Plan (3-year) best matches cost optimization with flexibility for growth and changes.

Cluster Placement Group: This type of placement group is designed to provide low-latency network performance and high throughput by grouping instances within a single Availability Zone. It is ideal for applications that require tightly coupled node-to-node communication.

Configuration:

When launching EC2 instances, specify the option to launch them in a cluster placement group.

This ensures that the instances are physically located close to each other, reducing latency and increasing network throughput.

Benefits:

Low-Latency Communication: Instances in a cluster placement group benefit from enhanced networking capabilities, enabling low-latency communication.

High Network Throughput: The network performance within a cluster placement group is optimized for high throughput, which is essential for HPC workloads.

AWS Backup is a fully managed backup service that can create backup plans for EC2 instances, including both instance configurations and attached EBS volumes, with scheduled and cross-Region copy capabilities. By adding the EC2 instances to the resource assignment in the backup plan, AWS Backup automatically backs up all configurations and attached EBS volumes, and can copy backups to a secondary Region for disaster recovery, providing the highest operational efficiency with the least manual effort.

AWS Documentation Extract:

“AWS Backup provides fully managed backup for EC2 instances and attached EBS volumes, with scheduling, retention, and cross-Region copy built in. By adding the EC2 instance as a resource, the backup includes both configuration and attached volumes.”

(Source: AWS Backup documentation)

A, D: Custom Lambda scripts increase operational overhead and are not as integrated or robust as AWS Backup.

C: Assigning only EBS volumes does not include the EC2 instance configuration, which is needed for full recovery.

Amazon S3 Express One Zone provides single-digit millisecond latency and high throughput, making it ideal for ML workloads that require multiple compute nodes and fast access. It is also more cost-effective than traditional file or block storage for temporary, high-speed needs.

The requirements include:

Scalability: The solution must scale as video files are uploaded.

Long-running tasks: Processing tasks can take up to 30 minutes. AWS Lambda has a maximum execution time of 15 minutes, which rules out options that involve Lambda performing all the processing.

Serverless and event-driven architecture: Ensures cost-effectiveness and high availability.

Analysis of Options:

Option A:

AWS Lambda has a 15-minute timeout, which cannot support tasks that take up to 30 minutes.

EventBridge Scheduler is unnecessary for monitoring files when native event notifications are available.Not a valid choice.

Option B:

AWS Step Functions and AWS Fargate can handle long-running processes, but Amazon EFS is not the ideal storage for uploaded video files in a serverless architecture.

Processing tasks triggered by EFS events are not a common pattern and may introduce complexities.Not the best practice.

Option C:

Amazon S3 is used for storing uploaded files, which integrates natively with event-driven services like EventBridge and Step Functions.

Amazon S3 event notifications trigger a Step Functions workflow, which can orchestrate Fargate tasks to process large video files, meeting the scalability and execution time requirements.Correct choice.

Option D:

Similar to Option A, AWS Lambda cannot handle long-running processes due to its 15-minute timeout.

Invoking Lambda for processing directly is not feasible for tasks that take up to 30 minutes.Not a valid choice.

AWS References:

Amazon S3 Event Notifications:AWS Documentation - S3 Event Notifications

AWS Step Functions:AWS Documentation - Step Functions

AWS Fargate:AWS Documentation - Fargate

Comparison of Storage Services:AWS Storage Options

By leveragingAmazon S3,Step Functions, andFargate, this solution provides a scalable, efficient, and serverless approach to handling video processing tasks.

The requirement that the security team manage key lifecycle actions such as creation, deletion, and rotation points tocustomer managed AWS KMS keys, not SSE-S3. Customer managed KMS keys allow fine-grained IAM authorization for both the Lambda execution role and the security administrator group. That supports least privilege because the Lambda role can be restricted to decrypt usage, while the administrator group can be limited to the KMS management actions it actually needs. The other answers either do not provide the required KMS management control or grant permissions too broadly. Therefore, using customer managed KMS keys with separate, scoped IAM permissions for decryption and key administration is the correct design.

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Stopping the DB instance is the most cost-effective option among the choices because it preserves the database for later restart without continuously paying for compute. AWS documents that a stopped RDS DB instance retains its metadata and can be restarted when needed, and that stopped instances automatically restart after 7 days. In practice, this means the company can periodically stop and restart the instance as required for short testing windows. The other options introduce unnecessary rebuild work or architecture changes. While the question wording includes both stop-db-cluster and stop-db-instance, the practical intent is clearly to stop the RDS MySQL instance temporarily and restart it when needed.

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