SAA-C03 Exam Simulation — 100 Questions

Question 1

A content publishing system uses Lambda functions that call an unreliable third-party API. Failed events must be retained for later investigation after retries are exhausted. What should be configured? The team wants the control to be enforceable during normal operations.

Accepted Answer

A Lambda dead-letter queue or failure destination. Option D is correct because a Lambda dead-letter queue (DLQ) or failure destination allows you to capture events that have exhausted all retry attempts from an asynchronous invocation. This ensures failed events are retained in Amazon SQS or SNS for later investigation, providing enforceable control during normal operations without impacting the function's ability to process successful events.

Answer

Lambda reserved concurrency set to zero

Answer

A larger deployment package

Answer

CloudFront error pages

Question 2

A startup runs two EC2-based workloads in the same AWS Region. Its customer-facing API is always on, and its nightly video transcoding fleet can restart jobs from checkpoints if an instance is interrupted. The finance team wants the lowest monthly compute cost without changing the application design. Which two actions should the team take? Select two.

Accepted Answer

Buy a Compute Savings Plan to cover the always-on API baseline usage.. Option B is correct because a Compute Savings Plan offers the lowest cost for steady-state workloads like the always-on API, providing up to 66% savings over On-Demand in exchange for a 1- or 3-year commitment. It applies to any EC2 instance family within a Region, making it flexible and cost-effective for the baseline usage. Option C is correct because Spot Instances can be up to 90% cheaper than On-Demand and are ideal for fault-tolerant workloads like the transcoding fleet, which can resume from checkpoints if interrupted.

Answer

Purchase an All Upfront Reserved Instance for the transcoding fleet only.

Answer

Increase the API instance size so CPU utilization stays below 30 percent.

Answer

Move the API tier to Dedicated Hosts to improve isolation and lower spend.

Question 3

A warehouse integration service must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Amazon EFS with mount targets in multiple Availability Zones. Amazon EFS provides a fully managed, NFS-based shared file system that can be mounted concurrently by multiple Linux EC2 instances across different Availability Zones. By creating mount targets in each AZ, the file system remains accessible even if one AZ fails, as traffic is automatically routed to the surviving mount targets. This meets the requirement for shared, resilient storage with a managed AWS-native control plane.

Answer

S3 mounted as a POSIX file system without a file gateway

Answer

Instance store volumes

Answer

An EBS volume attached to all instances

Question 4

A team runs a stateless web app on Amazon EC2 behind an Application Load Balancer. During traffic spikes, new EC2 instances take several minutes to finish bootstrapping before they can receive traffic. Which Auto Scaling configuration most directly reduces the time until additional capacity is available?

Accepted Answer

Use an Auto Scaling warm pool so pre-initialized instances are ready to enter service.. Option B is correct because an Auto Scaling warm pool allows you to maintain a pool of pre-initialized instances that are ready to quickly enter the target group and start serving traffic. Instead of waiting for new instances to boot and configure during a scale-out event, the warm pool provides instances that have already completed bootstrapping, drastically reducing the time to additional capacity.

Answer

Increase the ALB target group deregistration delay.

Answer

Reduce the Auto Scaling group minimum size to one instance.

Answer

Replace the Application Load Balancer with a Network Load Balancer.

Question 5

A service in private subnets downloads product images from Amazon S3 and stores job state in DynamoDB. A NAT Gateway is currently the only route to AWS services, and the monthly bill is dominated by NAT data processing charges. Which two changes will most directly reduce that cost? Select two.

Accepted Answer

Create a gateway VPC endpoint for Amazon S3.. A is correct because a gateway VPC endpoint for Amazon S3 allows instances in private subnets to access S3 directly over the AWS network without traversing the internet or a NAT Gateway. This eliminates NAT data processing charges for S3 traffic, which is the dominant cost driver in this scenario.

Answer

Add an internet gateway and move the instances into public subnets.

Answer

Replace the NAT Gateway with a Site-to-Site VPN connection.

Answer

Create an interface endpoint for S3 instead of a gateway endpoint.

Question 6

A static site is hosted in Amazon S3 and delivered by CloudFront. After a frontend release, the same JavaScript bundles are fetched repeatedly from the origin. Logs show that requests include unneeded query strings and cookies, which prevent cache reuse. Which two changes should the team make to reduce origin traffic and cost? Select two.

Accepted Answer

Configure a CloudFront cache policy that forwards only the query strings, headers, and cookies the app actually needs.. Option A is correct because CloudFront cache policies allow you to explicitly control which query strings, headers, and cookies are forwarded to the origin. By forwarding only the parameters the application actually needs, you prevent cache keys from being polluted by unneeded values, which increases the cache hit ratio and reduces requests to the S3 origin. This directly addresses the problem of repeated fetches caused by extraneous query strings and cookies.

Answer

Increase the size of the S3 bucket.

Answer

Place an Application Load Balancer in front of S3.

Answer

Disable caching so clients always get the latest files.

Question 7

A static website uses an Amazon S3 bucket as the origin for an Amazon CloudFront distribution. The team accidentally configured the S3 bucket policy to allow s3:GetObject to Principal "*", so objects are accessible via direct S3 URLs. They want to ensure objects are retrievable only through CloudFront. What is the best corrective action?

Accepted Answer

Remove public access from the bucket and update the bucket policy to allow GetObject only from CloudFront using the distribution’s SourceArn (and use CloudFront origin access control or origin access identity).. Option A is correct because the S3 bucket policy currently allows s3:GetObject from any principal, making objects publicly accessible via direct S3 URLs. By removing public access and updating the policy to restrict GetObject to only requests that originate from the CloudFront distribution (using either Origin Access Control or Origin Access Identity), objects become retrievable exclusively through CloudFront, preventing direct S3 access.

Answer

Enable S3 static website hosting and disable CloudFront, because website hosting blocks direct object URL access.

Answer

Add a WAF rule that rate-limits requests to the S3 bucket domain to make direct access impractical.

Answer

Turn on S3 object versioning so that attackers cannot read previous objects.

Question 8

A service processes messages from an Amazon SQS queue. Sometimes the worker finishes the business logic but does not delete the message before the visibility timeout expires, so the message is delivered again. Which two changes improve resilience and reduce the impact of duplicate processing? Select two.

Accepted Answer

Make the message handler idempotent.. Option A is correct because making the message handler idempotent ensures that even if a message is processed multiple times (due to visibility timeout expiry), the business outcome remains the same. Idempotency is a key design pattern for resilient architectures when using at-least-once delivery systems like SQS. Option B is correct because setting the visibility timeout long enough for normal processing prevents premature redelivery, reducing the chance of duplicate processing in the first place.

Answer

Switch from SQS to Amazon SNS for reliable buffering.

Answer

Shorten the queue retention period so messages expire quickly.

Answer

Disable retries in the consumer application.

Question 9

A SaaS vendor’s automation account in Account B needs to assume a role in a customer account in Account A to read a specific S3 bucket and publish a deployment status file. The customer is worried about confused deputy attacks because multiple customers use the same vendor software. Which trust-policy design best meets the requirement?

Accepted Answer

Allow only the vendor’s specific IAM principal to assume the role and require a unique sts:ExternalId condition.. Option B is correct because the `sts:ExternalId` condition is specifically designed to prevent the confused deputy problem in cross-account role assumptions. By requiring a unique external ID that only the customer knows, the customer ensures that the vendor's automation can only assume the role when acting on behalf of that specific customer, even if multiple customers use the same vendor software.

Answer

Allow the Account B root principal to assume the role if the caller knows the role ARN.

Answer

Attach a permissions boundary to the role so that the vendor cannot exceed the approved permissions.

Answer

Require MFA for the role assumption because it ensures only the vendor’s production automation can use the role.

Question 10

A single EC2 instance hosts a low-latency database cache that writes a large random working set to block storage. The application needs sustained high IOPS and low latency, and the storage must remain attached to the instance while it runs. Which two design choices best meet the requirement? Select two.

Accepted Answer

Use an io2 Block Express EBS volume for the highest sustained IOPS and low-latency performance.. Option A is correct because io2 Block Express EBS volumes are designed for mission-critical workloads requiring sustained high IOPS and low latency. They offer up to 256,000 IOPS per volume with sub-millisecond latency, making them ideal for a low-latency database cache that writes a large random working set to block storage. The storage remains attached to the EC2 instance while it runs, meeting the requirement for persistent block-level storage.

Answer

Use an S3 bucket as the backing store because object storage scales automatically.

Answer

Choose a cold HDD-based volume so the cache has durable low-cost storage.

Answer

Use the root volume from a T-series instance because burst credits can absorb the write spikes.

Question 11

A serverless checkout API uses AWS Lambda behind API Gateway. Every weekday at 09:00 UTC, marketing triggers a predictable surge. The first few minutes after each surge show cold-start latency, but traffic volume is forecastable and the business wants stable p95 latency. Which two changes should the team implement? Select two.

Accepted Answer

Publish a Lambda version and attach provisioned concurrency to an alias that points to that version.. Provisioned concurrency keeps a specified number of Lambda execution environments initialized and ready to respond immediately, eliminating cold starts for predictable traffic patterns. By publishing a Lambda version and attaching provisioned concurrency to an alias pointing to that version, the team ensures that the surge at 09:00 UTC is handled without cold-start latency, stabilizing p95 latency.

Answer

Increase the Lambda timeout so the function has more time to initialize during the spike.

Answer

Double the memory size during the spike without changing the concurrency model.

Answer

Move the function into more Availability Zones so the platform can spread cold starts across regions.

Question 12

A system processes events from Amazon SQS and sometimes sees duplicate messages due to retries. The business requirement is that each payment must be charged at most once. What design choice best addresses this resiliency requirement?

Accepted Answer

Implement idempotent processing using a deduplication key (for example, paymentId) and record completed charges so duplicates are safely ignored.. Option B is correct because implementing idempotent processing with a deduplication key (e.g., paymentId) ensures that even if duplicate messages arrive from SQS (due to retries or at-least-once delivery), the consumer can check a record of completed charges and safely ignore duplicates. This satisfies the business requirement of charging each payment at most once without relying on SQS’s best-effort deduplication or message ordering.

Answer

Assume duplicates never occur because the consumer deletes messages immediately after receiving them.

Answer

Increase the SQS visibility timeout until duplicates never happen.

Answer

Use SNS topics instead of SQS so retries are disabled by default.

Question 13

A warehouse integration service must process every event at least once, but duplicate processing is acceptable if the consumer handles idempotency. Which eventing approach is most suitable? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Use Amazon SQS standard queue and design consumers to be idempotent. Amazon SQS standard queues provide at-least-once delivery, which guarantees that every message is processed at least once, meeting the requirement that every event must be processed. Duplicate processing is acceptable because the consumer can be designed to handle idempotency. This is a managed, AWS-native service that aligns with the architecture review board's preference.

Answer

Use CloudFront signed URLs

Answer

Use UDP messages sent directly to workers

Answer

Use an in-memory queue on one EC2 instance

Question 14

A system uses multiple AWS Lambda functions behind different event sources. One Lambda occasionally spikes and causes other Lambdas to be throttled due to shared concurrency limits. Which setting best helps ensure the important Lambda keeps capacity during spikes?

Accepted Answer

Set Reserved Concurrency for the important Lambda function.. Reserved Concurrency guarantees that the important Lambda function always has a set number of concurrent executions available, preventing other functions from consuming the account-level concurrency pool and throttling it during spikes. This setting isolates the function's capacity from shared contention, ensuring its performance remains stable.

Answer

Increase the function timeout so throttling is less likely.

Answer

Enable Provisioned Concurrency for every Lambda in the account.

Answer

Reduce the number of IAM policies attached to the Lambda roles.

Question 15

A workload runs in private subnets and must reach Amazon S3 and AWS Secrets Manager without using the internet or a NAT gateway. The team wants to keep the traffic on AWS private networking and avoid public IPs. Which two changes should the architect make? Select two.

Accepted Answer

Create an S3 gateway VPC endpoint and update the route tables for the private subnets.. Option A is correct because an S3 gateway VPC endpoint allows private subnet instances to access S3 via AWS's private network without needing internet access or a NAT gateway. The endpoint uses route table entries to direct S3 traffic through the gateway, which is a horizontally scaled, redundant component that does not require public IPs.

Answer

Place a NAT gateway in the public subnet so the private instances can reach AWS services.

Answer

Assign public IPv4 addresses to the instances and restrict them with security groups.

Answer

Use VPC peering to the AWS service endpoints instead of VPC endpoints.

Question 16

A solutions architect is designing an S3 bucket for a IoT ingestion API. The objects must never be publicly accessible, even if a developer later adds an overly broad bucket policy. What should the architect configure? The design must avoid adding custom operational scripts.

Accepted Answer

Enable S3 Block Public Access at the account or bucket level. Option C is correct because S3 Block Public Access provides a definitive override that prevents any public access to objects, regardless of bucket policies or object ACLs. This setting, when enabled at the account or bucket level, ensures that even if a developer later attaches an overly permissive bucket policy, the public access is blocked. It meets the requirement of avoiding custom operational scripts by being a native, configurable S3 feature.

Answer

Enable S3 Transfer Acceleration

Answer

Create an IAM policy that denies s3:GetObject to anonymous users

Answer

Enable server access logging on the bucket

Question 17

A team wants to delegate IAM management to developers, but must ensure developers can never grant themselves permissions beyond a specific limit. Which AWS mechanism best matches this requirement?

Accepted Answer

Use an IAM permission boundary on roles/users that developers create, so the developers’ effective permissions are capped by the boundary policy.. IAM permission boundaries are the correct mechanism because they allow a developer to create IAM roles or users, but explicitly cap the maximum permissions those entities can have. The boundary policy acts as a ceiling, so even if a developer attaches a permissive managed policy, the effective permissions are the intersection of the boundary and the attached policy. This directly enforces the requirement that developers cannot grant themselves permissions beyond a specific limit.

Answer

Rely only on their IAM managed policies and instruct developers to self-check against internal guidelines.

Answer

Use a service control policy (SCP) that applies only to the developers’ IAM users in the account.

Answer

Use a KMS key policy to restrict IAM actions, because IAM actions can be controlled with KMS.

Question 18

A solutions architect is designing an S3 bucket for a healthcare document service. The objects must never be publicly accessible, even if a developer later adds an overly broad bucket policy. What should the architect configure?

Accepted Answer

Enable S3 Block Public Access at the account or bucket level. Option D is correct because S3 Block Public Access provides a definitive override that prevents any public access to objects, regardless of bucket policies or object ACLs. When enabled at the account or bucket level, it blocks all public access settings, ensuring that even if a developer later adds an overly broad bucket policy, the objects remain inaccessible to anonymous users. This is essential for compliance with healthcare regulations like HIPAA, where data must never be publicly exposed.

Answer

Enable server access logging on the bucket

Answer

Enable S3 Transfer Acceleration

Answer

Create an IAM policy that denies s3:GetObject to anonymous users

Question 19

A solutions architect is designing an S3 bucket for a claims portal. The objects must never be publicly accessible, even if a developer later adds an overly broad bucket policy. What should the architect configure? The design must avoid adding custom operational scripts.

Accepted Answer

Enable S3 Block Public Access at the account or bucket level. Option A is correct because S3 Block Public Access provides a definitive override that prevents any public access to S3 objects, even if a bucket policy or ACL later grants public access. This setting can be applied at the account or bucket level and ensures that all access is denied to anonymous users, meeting the requirement without custom scripts.

Answer

Create an IAM policy that denies s3:GetObject to anonymous users

Answer

Enable server access logging on the bucket

Answer

Enable S3 Transfer Acceleration

Question 20

You want to protect an Application Load Balancer (ALB) from common web exploits using AWS WAF. The application is not using CloudFront. Which AWS WAF deployment scope should you choose so the WAF rules apply to the ALB?

Accepted Answer

Use AWS WAF regional scope (associate the web ACL with the ALB resource). AWS WAF offers two deployment scopes: regional and CloudFront (global). Since the application is using an Application Load Balancer (ALB) without CloudFront, you must choose the regional scope. This allows you to associate the web ACL directly with the ALB resource, enabling AWS WAF to inspect HTTP/HTTPS requests for common web exploits like SQL injection and cross-site scripting (XSS) at the regional endpoint.

Answer

Use AWS WAF CloudFront (global) scope and associate the web ACL with the ALB

Answer

Use AWS Shield Advanced and rely on it to inspect payloads for SQL injection and XSS

Answer

Use security groups only, because they can detect SQL injection patterns in HTTP requests