SAA-C03 Quick Quiz — 10 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.