SAA-C03 Amazon Web Services AWS Certified Solutions Architect - Associate (SAA-C03) Free Practice Exam Questions (2026 Updated)

Comprehensive and Detailed Step-by-Step Explanation:

To accurately charge customers based on their monthly data download usage, the following solution is recommended:

Structured Logging Configuration:

Action:Ensure that the AWS Transfer for SFTP server is configured to log user activity, including details about file downloads, to Amazon S3 in a structured format.

Implementation:Utilize AWS Transfer Family ' s structured logging feature to capture detailed information about user sessions, including actions performed and data transferred.

docs.aws.amazon.com

Justification:Structured logs provide comprehensive data necessary for analyzing customer-specific download activities.

Data Analysis with Amazon Athena:

Action:Use Amazon Athena to run SQL queries on the structured log data stored in the S3 bucket to calculate the amount of data each customer has downloaded.

Implementation:

a.Define a Schema:Create a table in Athena that maps to the structure of your log files. This involves specifying the format of the logs and the location in S3.

b.Query Data:Write SQL queries to sum the total bytes downloaded by each customer over the billing period. This can be achieved by filtering logs based on user identifiers and summing the data transfer amounts.

Justification:Athena allows for efficient querying

Amazon Athena provides a cost-effective, serverless way to query data without affecting the performance of DynamoDB. By using the Athena DynamoDB connector, the company can perform the necessary SQL queries without consuming read capacity on the DynamoDB table, which is essential for minimizing impact on provisioned throughput.

Key benefits:

Minimal Impact on Provisioned Capacity: Athena queries do not directly impact DynamoDB’s read capacity, making it ideal for running analytics without affecting the customer-facing workloads.

Cost-Effective: Athena is a serverless solution, meaning you pay only for the queries you run, making it highly cost-effective compared to running a dedicated cluster like Amazon EMR or Redshift.

AWS Documentation: The use of Athena to query DynamoDB through its connector aligns with AWS ' s best practices for performance efficiency and cost optimization​​.

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.

The best answer ismessage batching. AWS documentation explains that SQS batch actions let applications send, receive, or delete up to 10 messages at a time. AWS also notes that batching can be combined with horizontal scaling to improve throughput with fewer requests and connections. That makes batching the most relevant feature for handling sudden traffic increases efficiently. FIFO queues address strict ordering and deduplication, visibility timeout controls how long a received message stays hidden from other consumers, and long polling reduces empty responses and unnecessary polling cost. None of those features directly improve throughput as effectively as batching for traffic spikes.

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Edge-optimized API endpointsroute requests through CloudFront, reducing latency for global users.

Option Acorrectly implements edge-optimization, caching, and compression to minimize latency.

Options B and Ddo not use edge optimization, leading to higher latency for global users.

Reserved concurrency inOptions C and Dimproves backend scaling but does not address global latency directly.

Export Requirements:

To export data from DynamoDB to Amazon S3, point-in-time recovery (PITR) must be enabled for the tables. This feature creates a snapshot of the data, which is essential for exports.

Incorrect Options Analysis:

Option B: S3 buckets and DynamoDB tables do not need to be in the same region for exports.

Option C: DynamoDB streams are unrelated to the export functionality.

Option D: DAX accelerates reads but has no role in exports.

For improving availability and performance of the hybrid application, the following solutions are optimal:

AWS Global Accelerator (Option A): Global Accelerator provides high availability and improves performance by using the AWS global network to route user traffic to the nearest healthy endpoint (across AWS Regions). By adding the Network Load Balancers as endpoints, Global Accelerator ensures that traffic is routed efficiently to the closest endpoint, improving both availability and performance.

Network Load Balancer (Option D): Thestateful TCP-based workloadhosted on Amazon EC2 instances and thestateless UDP-based workloadhosted on-premises are best served by Network Load Balancers (NLBs). NLBs are designed to handle TCP and UDP traffic with ultra-low latency and can route traffic to both EC2 and on-premises endpoints.

Option B (CloudFront and Route 53): CloudFront is better suited for HTTP/HTTPS workloads, not for TCP/UDP-based applications.

Option C (ALB): Application Load Balancers do not support the stateless UDP-based workload, making NLBs the better choice for both TCP and UDP.

AWS References:

AWS Global Accelerator

Network Load Balancer

The best solution is to useAmazon SQSto receive updates from the mobile app and process them with anAWS Lambdafunction. The Lambda function can rewrite the message body as necessary for each shipper and then publish the updates to the appropriateSNS topicfor distribution. Thissetup ensures that each shipper receives only the relevant data and minimizes operational overhead by using managed services.

Option A (SNS filter policy): SNS does not have the capability to rewrite message bodies before forwarding.

Option C (Second SNS topic): Using an additional SNS topic adds unnecessary complexity without solving the message rewriting requirement.

Option D (EventBridge Pipes): EventBridge Pipes is more complex than necessary for this use case, and Lambda can handle the logic more efficiently.

AWS References:

Amazon SQS

Amazon SNS with Lambda

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.

When an AWS Lambda function is invoked, especially after periods of inactivity, it may experience cold starts that delay execution. As demand increases, the scaling behavior and latency of Lambda can affect performance. Provisioned Concurrency is an AWS feature designed specifically to solve this issue.

From AWS Documentation:

“Provisioned Concurrency keeps functions initialized and hyper-ready to respond in double-digit milliseconds.”

(Source: AWS Lambda Developer Guide – Managing Concurrency)

Why Option D is correct:

Provisioned Concurrency ensures that a specified number of Lambda function instances are always warm and ready to serve requests, eliminating cold start latency.

It ' s cost-effective for workloads with consistent usage patterns, like real-time simulations for a small user group.

Maintains scalability and low overhead of Lambda without moving to managed container or EC2 platforms.

Why the other options are less optimal:

Option A (Fargate) and Option B (EC2): Introduce more infrastructure and higher ongoing costs for a small team with likely intermittent usage.

Option C (AWS Batch): Ideal for batch jobs, not real-time simulations; also incurs higher latency due to job queuing.

Amazon S3 supports one Lifecycle configuration per bucket that can contain multiple rules. Lifecycle rules can include filters, including object size filters: ObjectSizeGreaterThan and ObjectSizeLessThan. You can combine rules so that one targets large objects and another provides a default expiration. Here, configure Rule 1 with a size filter ObjectSizeGreaterThan = 1 TB and Expiration = 2 days (48 hours) to purge very large videos early. Configure Rule 2 with Expiration = 7 days without a size filter to serve as a catch-all maximum retention for all objects. Options B and D are invalid because S3 does not allow multiple Lifecycle configurations per bucket. Option C cannot distinguish large files; it would delete all files at the same schedule without honoring the 48-hour policy for > 1 TB objects. This single configuration with two rules meets both retention targets with minimal overhead and full S3-native capability.

The right solution isAPI Gateway + Lambda + Amazon Comprehend + DynamoDB. AWS documents that Amazon Comprehend is the NLP service for detecting entities, sentiment, and key phrases, which matches the workload exactly. DynamoDB is a fully managed, distributed database designed for high-throughput workloads and single-digit millisecond performance at scale, making it a strong fit for a highly available application handling many concurrent requests. The other answers misuse services: Amazon Translate is for translation, Amazon Textract is for extracting text from documents, and ElastiCache is a cache rather than the durable primary database described in the question. This makes option A the only architecture that aligns with both the NLP functions and the scalable database requirement. (AWS Documentation)

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The correct and secure approach is to use Amazon CloudFront with Origin Access Control (OAC) to protect the S3 origin and attach AWS WAF to the CloudFront distribution to inspect and filter traffic at the edge before reaching the origin.

From AWS Documentation:

“AWS WAF is integrated with Amazon CloudFront, allowing inspection of HTTP(S) requests at the edge location before forwarding to your origin. To restrict direct access to the S3 bucket, use Origin Access Control (OAC).”

(Source: Amazon CloudFront Developer Guide – Serving private content)

Why Option D is correct:

CloudFront is the only service that integrates with AWS WAF for full HTTP layer inspection.

Origin Access Control (OAC) ensures that only CloudFront can access the S3 origin—replacing older Origin Access Identity (OAI) features.

The S3 bucket policy is configured to trust requests only from CloudFront using OAC signed requests.

Why the other options are incorrect:

Option A: WAF ARN is not a principal in S3 bucket policy. IAM does not support bucket policies based on WAF ARNs.

Option B: Incorrect – CloudFront doesn ' t " forward requests to WAF " ; rather, WAF is associated with CloudFront and inspects requests at the edge.

Option C: S3 does not use security groups; they are for EC2/network interfaces. This shows a misunderstanding of how S3 works.

Amazon RDS supports encryption at rest by using AWS KMS keys backed by AWS CloudHSM. This allows use of dedicated FIPS 140-2 Level 3 validated hardware modules to manage encryption keys, meeting compliance for sensitive data such as PII.

From AWS Documentation:

“You can use AWS KMS with keys that are backed by AWS CloudHSM to control the encryption of RDS databases. This provides dedicated HSM-backed key storage and management.”

(Source: Amazon RDS User Guide – Encrypting Amazon RDS Resources)

Why B is correct:

Meets the requirement for dedicated HSM hardware.

Fully integrates with RDS for transparent encryption at rest.

Satisfies compliance standards for healthcare and regulated data.

Why others are incorrect:

A: Keys in CloudHSM directly are not used by RDS; they must be managed through KMS integration.

C: EC2 instance stores are ephemeral, not suitable for RDS databases.

D: SSE-S3 applies to S3 objects, not databases.

TheGateway Load Balancer (GWLB)is specifically designed to route traffic through a security appliance in a hub-and-spoke model, making it the ideal solution for inspecting traffic between multiple AWS accounts. GWLB enables you to simplify, scale, and deploy third-party virtual appliances transparently, and it can work across multiple VPCs or accounts using interface endpoints (Gateway Load Balancer Endpoints).

Key AWS features:

Traffic Inspection: The GWLB allows the centralized security appliance to inspect traffic between different VPCs, making it suitable for inspecting inter-account interactions.

Interface VPC Endpoints: By using interface endpoints in the application accounts, traffic can securely and efficiently be routed to the security appliance in the networking account.

AWS Documentation: The use of GWLB aligns with AWS’s best practices for centralized network security, simplifying architecture and reducing operational complexity​.

DynamoDB export to Amazon S3 (via point-in-time exports or table backups) “does not consume read capacity” and has no impact on table performance. Once data is in S3, Amazon Redshift can ingest efficiently with COPY from S3, which is the standard, parallel, high-throughput load path with minimal management. Direct COPY from DynamoDB (B) performs a table scan that can consume provisioned throughput, risking throttling. Building Lambda pipelines (C) adds custom code and scheduling overhead. Athena federated queries (D) are ad hoc analytics, not optimized for bulk, recurring warehouse loads. Therefore, exporting to S3 and loading with Redshift COPY maintains DynamoDB throughput and minimizes operational burden.

Amazon Route 53 supports failover routing policies, which use health checks to route DNS queries to a secondary Region only if the primary endpoint fails. This design ensures only one Region is active for traffic at any given time. This is the recommended architecture for active-passive, multi-Region DR strategies.

AWS Documentation Extract:

“Failover routing lets you route traffic to a primary resource, such as a web server in one Region, and a secondary resource in another Region. If the primary fails, Route 53 can route traffic to the secondary resource automatically.”

(Source: Amazon Route 53 documentation, Routing Policy Types)

A, D: These options do not configure DNS failover for external users.

C: Geolocation routing is for regional distribution, not DR failover.

AWS recommends using Amazon ElastiCache as an in-memory caching layer in front of relational databases such as Amazon RDS to offload read traffic and significantly improve performance for read-heavy workloads. ElastiCache (Redis OSS) provides microsecond latency and can cache the results of frequent or expensive queries without requiring any change to the underlying database schema or engine. This directly addresses the requirement to improve performance without changing the database structure and with minimal operational overhead, because ElastiCache is a fully managed service (patching, failure detection, replacement, etc., are handled by AWS).

Option A (DynamoDB) would require a full data migration and application changes, including schema and query rewrites.

Option C (Memcached on EC2) introduces additional management overhead for EC2 instances (scaling, patching, HA).

Option D (DAX) is a caching layer only for DynamoDB and cannot be used directly with Amazon RDS.

Big data workloads that need to process terabytes of data in memory requirememory-optimized instancesfor the core and task nodes to ensure sufficient memory for processing data efficiently.

Primary Node:Ageneral purpose instanceis suitable because it manages cluster operations, including coordination and monitoring, and does not process data directly.

Core and Task Nodes:These nodes handle data storage and processing.Memory-optimized instancesare ideal because they provide high memory-to-CPU ratios, which is critical for in-memory big data workloads.

Why Other Options Are Incorrect:

Option A:Storage optimized and compute optimized instances are not suitable for workloads that rely heavily on in-memory processing.

Option B:A memory-optimized primary node is unnecessary because the primary node does not process data.

Option D:General purpose instances for all nodes will not provide sufficient memory for processing terabytes of data in memory.

AWS Documentation References:

Amazon EMR Instance Types

Memory-Optimized Instances

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.

TheAWS_PROXY integration with Amazon API Gatewayallows the API to invoke a Lambda function synchronously, making it a suitable solution for the custom authorization mechanism and text translation use case.

Synchronous Invocation: The API Gateway REST API with AWS_PROXY integration enables synchronous processing of HTTP requests and responses, which is required for document translation.

Custom Authorization: API Gateway supports custom authorizers for fine-grained access control.

Lambda Function Execution: Although Lambda ' s execution time limit is 15 minutes, this is sufficient for the 6-minute document translation requirement.

Why Other Options Are Not Ideal:

Option B:

Introducing a Lambda function URL to invoke another Lambda function unnecessarily complicates the architecture.Not efficient.

Option C:

Asynchronous invocation cannot guarantee real-time response delivery for document translation tasks.Not suitable.

Option D:

Hosting the API on an EC2 instance increases operational overhead. HTTP PROXY integration does not add significant benefits here.Not cost-effective or efficient.

AWS References:

API Gateway Lambda Proxy Integration:AWS Documentation - Proxy Integration

Custom Authorization in API Gateway:AWS Documentation - Custom Authorization

AWS CloudTrail Lakeis a fully managed service that allows the collection, storage, and querying ofCloudTrail eventsfor both AWS and non-AWS services. CloudTrail Lake can be customized to collect logs from various sources, ensuring a centralized audit solution. It also supports long-term storage, so logs can be retained for 7 years, meeting the compliance requirement.

Option A (Data Lake): Setting up a data lake in S3 introduces unnecessary operational complexity compared to CloudTrail Lake.

Option C (Ingest non-AWS services into CloudTrail): CloudTrail Lake is better suited for this task with less operational overhead.

Option D (CloudWatch Logs): While CloudWatch can store logs, CloudTrail Lake is specifically designed for API auditing and storage.

AWS References:

AWS CloudTrail Lake

This workload has two distinct needs: (1) a managed way for external clients to upload files using a familiar managed file transfer protocol, and (2) an automated, low-ops method to run a watermarking step and store the resulting images as objects. AWS Transfer Family provides a fully managed capability to receive files over protocols such as SFTP, while landing those files directly into Amazon S3 as objects. That directly satisfies the requirement that “uploaded images must be stored as objects” with minimal infrastructure management.

To automate watermarking with minimal operational overhead, invoking AWS Lambda is a strong fit. Lambda is serverless and scales automatically with incoming uploads, and it can run the watermarking logic as code without managing servers. Transfer Family supports managed workflows that can orchestrate post-upload actions; using a Transfer Family workflow to invoke a Lambda function provides a clean, managed, event-driven pipeline: clients upload via SFTP → objects land in S3 → workflow triggers watermark processing → output is written back to S3.

Option A adds operational burden by requiring an EC2-based application tier for watermarking, which increases patching and scaling responsibilities. Option B can work (S3 + Batch), but it requires building and operating the upload mechanism (REST APIs) and typically more orchestration than necessary for simple “upload then process” flows; Batch is better when you need large-scale, long-running batch compute rather than lightweight per-object processing. Option D is unsuitable because S3 Glacier Deep Archive is intended for long-term archival with slow retrieval, which conflicts with active workflow processing and watermark automation.

Therefore, C best meets the requirements using managed services end-to-end: Transfer Family for ingestion, S3 for object storage, and Lambda for automated watermarking.

The best practice for granting AWS resource access to EC2 instances is to use IAM roles, not users or long-lived access keys. You create an IAM role with a policy that grants the minimum permissions required, then attach that role to an instance profile associated with the EC2 instance. The instance then automatically receives temporary credentials for AWS service access.

AWS Documentation Extract:

" Attach an IAM role to your EC2 instances to securely grant permissions to AWS services according to the principle of least privilege. Never embed access keys in EC2 instances. "

(Source: AWS EC2 documentation, IAM Roles for EC2)

A, B: Using IAM users and embedding keys violates security best practices.

C: IAM role credentials are automatically managed and never need to be manually attached as keys.

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 data isfrequently accessed only for the first 30 daysand then israrely accessedbut must be retained for7 years. That pattern matchesAmazon S3 Standardfor the initial active period and thenS3 Glacier Deep Archivefor long-term retention at the lowest storage cost. AWS guidance positions Glacier Deep Archive for long-lived archive data that is accessed once or twice a year and is ideal for compliance-style retention. EFS and EBS are not cost-effective archival storage choices for this use case. S3 Standard-IA is cheaper than S3 Standard, but Glacier Deep Archive is more cost-optimized for multi-year rare access.

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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.

SAML 2.0-based federation allows organizations to integrate their on-premises Active Directory with AWS, enabling Single Sign-On (SSO) for AWS Management Console and AWS CLI/API access. This lets users continue using their existing AD credentials, removing the need to manage separate identities for AWS and on-premises systems. Mapping roles to AD groups provides granular access control and seamless management.

Reference Extract from AWS Documentation / Study Guide:

" AWS supports SAML 2.0 for federated access, enabling integration with Active Directory or other identity providers to provide single sign-on to AWS resources without creating separate IAM users. "

Source: AWS Certified Solutions Architect – Official Study Guide, Identity and Access Management section.

Amazon Aurora Serverless is a cost-effective, on-demand, autoscaling configuration for Amazon Aurora. It automatically adjusts the database ' s capacity based on the current demand, which is ideal for workloads with variable and unpredictable usage patterns. Since the application is expected to be read-heavy with occasional writes and steady growth, Aurora Serverless can provide the necessary performance without requiring the management of database instances.

Cost-Optimization: Aurora Serverless only charges for the database capacity you use, making it a more cost-effective solution compared to always running provisioned database instances, especially for workloads with fluctuating demand.

Scalability: It automatically scales database capacity up or down based on actual usage, ensuring that you always have the right amount of resources available.

Performance: Aurora Serverless is built on the same underlying storage as Amazon Aurora, providing high performance and availability.

Why Not Other Options?:

Option A (RDS with Provisioned IOPS SSD): While Provisioned IOPS SSD ensures consistent performance, it is generally more expensive and less flexible compared to the autoscaling nature of Aurora Serverless.

Option C (DynamoDB with On-Demand Capacity): DynamoDB is a NoSQL database and may not be the best fit for applications requiring relational database features.

Option D (RDS with Magnetic Storage and Read Replicas): Magnetic storage is outdated and generally slower. While read replicas help with read-heavy workloads, the overall performance might not be optimal, and magnetic storage doesn’t provide the necessary performance.

AWS References:

Amazon Aurora Serverless- Information on how Aurora Serverless works and its use cases.

Amazon Aurora Pricing- Details on the cost-effectiveness of Aurora Serverless.

AWS Fargate with Amazon ECS is a serverless, fully managed compute engine for containers. Fargate eliminates the need to provision or manage servers, and is ideal for periodic, long-running batch jobs. You only pay for the resources consumed during job execution, making it cost-effective for jobs that run infrequently. Lambda is not suitable because the maximum execution time is 15 minutes, but the job can take up to 2 hours.

AWS Documentation Extract:

“AWS Fargate lets you run containers without managing servers or clusters. Fargate is ideal for batch jobs, event-driven processing, and scheduled tasks that require hours of compute.”

(Source: AWS Fargate documentation)

A: Reserved Instances are cost-inefficient for infrequent workloads and require server management.

B: Lambda has a hard limit of 15 minutes per execution, insufficient for this job.

D: ECS on EC2 requires you to manage and provision EC2 instances, increasing cost and management overhead.

AWS Glue jobs are designed for extract, transform, and load (ETL) operations, which are perfect for transforming clinical trial data. AWS Glue integrates with AWS Key Management Service (KMS), allowing for customer-specific encryption keys, fulfilling the encryption requirement with minimal operational effort. Client-side encryption with AWS KMS ensures that the data is encrypted before it is sent to S3, aligning with the security needs specified in the scenario.

Key aspects:

AWS Glue: This managed ETL service simplifies data transformation, reduces operational overhead, and integrates seamlessly with KMS.

CSE-KMS: Client-side encryption with KMS ensures that the data is encrypted with customer-specific keys before it is processed or stored in S3, offering robust security​​.

Minimal Operational Overhead: Compared to managing an EMR cluster, AWS Glue automates much of the process, making it a lower-effort solution.

AWS Documentation: According to the AWS Well-Architected Framework, encryption with AWS KMS offers strong security controls that meet the needs of industries requiring high levels of confidentiality​​.

AWS Config has a built-in managed rule (access-keys-rotated) that evaluates IAM access key age. Config rules detect non-compliant resources automatically, without building custom logic.

After Config identifies old keys, EventBridge can trigger an AWS Lambda function to disable and delete the keys. Lambda provides a fully managed compute layer requiring no servers or batch environments.

Using AWS Batch (Options A, B, and D) adds unnecessary operational overhead for a simple automation task.

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The question asks for the most cost savings while not affecting application performance, and it explicitly calls out both compute costs and storage costs increasing. The best answer is the option that optimizes both cost drivers without reducing capacity needed for peak performance. Option D accomplishes this by combining two well-established cost optimization mechanisms: a Compute Savings Plan for baseline compute usage and S3 Lifecycle policies for lower-cost storage of older receipt images.

A Compute Savings Plan is best applied to the steady, always-needed portion of compute capacity. In an Auto Scaling group, there is typically a predictable minimum footprint that runs continuously. Purchasing a Savings Plan for that baseline delivers substantial discounts compared with On-Demand pricing while keeping performance unchanged. For traffic spikes, continuing to use On-Demand Instances is operationally simple and preserves scaling behavior and customer experience. This avoids the risk that reducing minimum capacity could introduce slower scale-out or insufficient resources during sudden load.

On the storage side, raw receipt images are stored in Amazon S3, and many applications access the newest objects most frequently. Using S3 Lifecycle policies to transition objects after 30 days to lower-cost tiers (such as infrequent access or archival tiers as appropriate for retrieval needs) reduces storage spend without changing how new uploads are handled or processed. It also keeps the application fast for recent receipts, where performance typically matters most.

Options A and B move storage to EFS, which is generally more expensive than S3 for object storage patterns and does not align with “stored as objects.” Option C reduces the maximum Auto Scaling capacity, which can directly harm performance during demand surges. Therefore, D provides the largest cost reduction while preserving performance and scaling characteristics.

The correct answers areA and D. The requirement is to replace third-party middleware with an AWS-native solution that supportsasynchronous communication,exactly-once delivery, and theleast infrastructure management.Amazon SQS FIFO queuesare the best messaging component because FIFO queues are designed for workloads that requireordered processingandexactly-once message deliverysemantics. That makes optionDthe correct messaging choice.

For the compute layer,AWS Lambdaprovides the least infrastructure management because it is a fully managed serverless compute service. Lambda removes the need to manage virtual machines, operating systems, or cluster infrastructure. It integrates naturally with queue-based asynchronous architectures and can be invoked to process messages from SQS while scaling automatically based on queue depth and workload demand. That makes optionAthe best choice for minimizing operational burden.

Option B is incorrect because EC2 instances would require the company to manage instance provisioning, patching, scaling, and availability. Option C is incorrect becauseAmazon SNSis a pub/sub messaging service and does not provide exactly-once delivery guarantees likeSQS FIFO. Option E is incorrect becauseAmazon EKSintroduces Kubernetes management overhead and is not the lowest-management compute option.

AWS best practices recommend using managed messaging and serverless compute to reduce undifferentiated operational work. For a migration that requires asynchronous processing with exactly-once delivery and minimal infrastructure management, the most appropriate architecture isAWS Lambda functionswithAmazon SQS FIFO queues.

The problem is scale-out latency: when traffic spikes, new instances take time to launch, initialize, and pass health checks. This can temporarily degrade user experience even if Auto Scaling eventually adds enough capacity. The goal is to improve responsiveness to sudden spikes cost-effectively.

A key Auto Scaling feature for this situation is an EC2 Auto Scaling warm pool. A warm pool maintains a set of pre-initialized instances (stopped or running, depending on configuration) that Auto Scaling can rapidly transition into service. This reduces the time needed for instance launch and initialization, enabling faster scale-out during unexpected surges.

Option B is best because it supports the application’s peak needs by ensuring Auto Scaling can scale up to the required maximum capacity and keeps warm capacity ready. While a warm pool has some cost (especially if instances are kept running), it is typically more cost-effective than permanently running peak capacity all the time. It improves user experience by minimizing cold start delays during spikes.

Option A is counterproductive: lowering minimum capacity increases the likelihood of scale-out delays. Option C is illogical as written (“increase maximum to meet normal demand”); maximum should reflect peak potential, and a warm pool without sufficient max headroom will not solve the spike problem. Option D uses scheduled scaling, but the spike is unexpected, and increasing instance sizes increases cost and does not address launch delay; it may also reduce horizontal scaling flexibility.

Therefore, B is the most cost-effective way to improve scale-out performance and protect user experience during unexpected bursts.

The correct answer isBbecause the company explicitly wants to move from amonolithic architectureto aloosely coupled architecturethat supportsindependent scaling. Refactoring the application intomicroservicesis the architectural approach that best meets that requirement. Running the microservices onAmazon ECScontainers provides a managed container orchestration platform with less operational overhead than managing a Kubernetes environment.

With microservices, separate business functions such as product catalog management and customer checkout can be deployed as individual services. Each service can scale independently based on its own traffic and performance characteristics. This is far more efficient than scaling the entire monolithic application when only one part of the system experiences increased demand.

AnApplication Load Balanceris appropriate because it can route HTTP and HTTPS traffic and supports path-based and host-based routing, which is useful for directing requests to different services. This design improves agility, performance, and operational flexibility while supporting the company’s need for growth.

Option A improves availability and scalability, but it still runs a copy of thesame monolithic applicationon multiple EC2 instances. That does not enable independent scaling of individual functions. Option C creates a basic two-tier design, but it is not a fully loosely coupled microservices architecture. Option D uses Amazon EKS but places the application into asingle container, which does not achieve independent scaling of separate components and introduces more operational complexity than necessary.

AWS architectural best practices recommend decomposing monoliths intomicroserviceswhen independent scaling, agility, and component isolation are required. Therefore,Amazon ECS with microservicesis the best solution.

AWS IAM Identity Center:

IAM Identity Centerprovides centralized access management for multiple AWS accounts within an organization and integrates seamlessly with existing identity providers (IdPs) throughSAML 2.0 federation.

It allows users to authenticate using their existing IdP credentials and gain access to AWS resources without the need to create and manage separate IAM users in each account.

IAM Identity Centeralso simplifies provisioning and de-provisioning users, as it can automatically synchronize users and groups from the external IdP to AWS, ensuring secure and managed access.

Integration with Existing IdP:

The solution involves configuringIAM Identity Centerto connect to the company ' s IdP using SAML. This setup allows employees to log in with their existing credentials, reducing the complexity of managing separate AWS credentials.

Once connected,IAM Identity Centerhandles authentication and authorization, granting users access to the AWS accounts based on their assigned roles and permissions.

Why the Other Options Are Incorrect:

Option A: Creating separateIAM usersfor each employee is not scalable or efficient. Managing thousands of IAM users across multiple AWS accounts introduces unnecessary complexity and operational overhead.

Option B: Using AWSroot userswith synchronized passwords is a security risk and goes against AWS best practices. Root accounts should never be used for day-to-day operations.

Option D:AWS Resource Access Manager (RAM)is used for sharing AWS resources between accounts, not for federating access for users across accounts. It doesn’t provide a solution for authentication via an external IdP.

AWS References:

AWS IAM Identity Center

SAML 2.0 Integration with AWS IAM Identity Center

By setting upIAM Identity Centerand connecting it to the existing IdP, the company can efficiently manage access for thousands of employees across multiple AWS accounts with a high degree of operational efficiency and security. Therefore,Option Cis the best solution.

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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