10 beginner questions on the DVA-C02 domains: Development with AWS Services (DynamoDB keys, SQS queues, retries), Security (Cognito user pools, S3 presigned URLs), Deployment (AWS SAM, Lambda aliases, CodeDeploy AppSpec) and Troubleshooting and Optimization (Lambda memory, AWS X-Ray).

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  1. A developer is designing an Amazon DynamoDB table for a busy application. Which partition key choice best spreads requests evenly across partitions?

    • A. A status attribute with the values active or inactive
    • B. A unique user ID for each of millions of users ✔ correct
    • C. The current date, shared by all of the day's records
    • D. A country code shared by most of the customers

    Answer: B. A partition key with many distinct values, requested fairly evenly, spreads traffic across partitions. Low-cardinality keys such as a status or the current date concentrate requests on a few partitions (hot partitions).

    Source: docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-partition-key-unifor · Domain: Development with AWS Services

  2. A CPU-intensive AWS Lambda function runs too slowly. Which configuration change gives the function more CPU power?

    • A. Increase the function timeout
    • B. Increase the memory setting ✔ correct
    • C. Add reserved concurrency
    • D. Add a Lambda layer

    Answer: B. Lambda allocates CPU power in proportion to the memory you configure, so raising memory also raises CPU. A longer timeout only allows more run time; reserved concurrency controls how many instances can run.

    Source: docs.aws.amazon.com/lambda/latest/dg/configuration-memory.html · Domain: Troubleshooting and Optimization

  3. Amazon SQS standard queues guarantee that messages are delivered exactly once and in the exact order they were sent.

    • A. True
    • B. False ✔ correct

    Answer: B. False. Standard queues give at-least-once delivery and best-effort ordering, so a message can arrive more than once or out of order. FIFO queues preserve order and prevent duplicates.

    Source: docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/standard-queu · Domain: Development with AWS Services

  4. A developer is building a mobile app. Its users must be able to sign up and sign in with a user name and password, and the developer does not want to run an identity server. Which service should be used?

    • A. One IAM user created for each app user
    • B. AWS Security Token Service called directly
    • C. AWS Directory Service for Microsoft AD
    • D. An Amazon Cognito user pool ✔ correct

    Answer: D. A Cognito user pool is a managed user directory for app sign-up and sign-in, including federation and MFA. IAM users are for people and workloads managing AWS, not for millions of app customers.

    Source: docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools.html · Domain: Security

  5. An application must let a customer download one private S3 object for a limited time, without making the bucket public or sharing AWS credentials. What should the developer generate?

    • A. A presigned URL for the object ✔ correct
    • B. A public-read ACL on the object
    • C. A new IAM user for the customer
    • D. A bucket policy allowing everyone

    Answer: A. A presigned URL uses the creator's security credentials to grant time-limited permission to download a specific object. The other options make the object public or hand out long-term credentials.

    Source: docs.aws.amazon.com/AmazonS3/latest/userguide/ShareObjectPreSignedURL.html · Domain: Security

  6. A developer has an AWS SAM project and has changed a function's code. Which two AWS SAM CLI commands prepare the updated application and deploy it to AWS? (Select TWO)

    • A. sam init
    • B. sam build ✔ correct
    • C. sam local invoke
    • D. sam deploy ✔ correct
    • E. sam logs

    Answer: B, D. sam build updates the build artifacts in the .aws-sam directory, and sam deploy deploys them. sam init creates a new project; sam local invoke runs a function locally.

    Source: docs.aws.amazon.com/serverless-application-model/latest/developerguide/using-sam · Domain: Deployment

  7. A developer wants 10% of a Lambda function's invocations to go to a new version, while the rest still use the current version. What should the developer configure?

    • A. Reserved concurrency on the new version
    • B. A Lambda layer containing the new code
    • C. A weighted alias that points to both versions ✔ correct
    • D. The $LATEST version for all callers

    Answer: C. A weighted alias splits traffic between two versions of the same function by percentage, so a small share of invocations can test the new version. Layers package shared code; they do not route traffic.

    Source: docs.aws.amazon.com/lambda/latest/dg/configuring-alias-routing.html · Domain: Deployment

  8. For an AWS CodeDeploy deployment to EC2 instances, which file in the application revision defines the files to copy and the lifecycle event hooks (scripts) to run?

    • A. buildspec.yml
    • B. samconfig.toml
    • C. template.yaml
    • D. appspec.yml ✔ correct

    Answer: D. The AppSpec file (appspec.yml for EC2/on-premises) tells CodeDeploy where to copy files and which scripts to run at each lifecycle event. buildspec.yml is used by CodeBuild.

    Source: docs.aws.amazon.com/codedeploy/latest/userguide/reference-appspec-file.html · Domain: Deployment

  9. Requests to a serverless application pass through Amazon API Gateway, AWS Lambda and Amazon DynamoDB. A developer needs to see where time is spent for each request. Which service helps most?

    • A. AWS X-Ray ✔ correct
    • B. AWS CloudTrail
    • C. AWS Config
    • D. AWS Trusted Advisor

    Answer: A. AWS X-Ray collects trace data as requests travel through the application and its downstream services, showing latency for each segment. CloudTrail records API calls for auditing, not request timing.

    Source: docs.aws.amazon.com/xray/latest/devguide/aws-xray.html · Domain: Troubleshooting and Optimization

  10. When an AWS service returns a throttling error, the recommended client behavior is to retry the request with exponential backoff and jitter.

    • A. True ✔ correct
    • B. False

    Answer: A. True. The AWS SDKs retry throttling and transient errors using exponential backoff with jitter, which spreads out retries from many clients so the service can recover instead of being flooded.

    Source: docs.aws.amazon.com/sdkref/latest/guide/feature-retry-behavior.html · Domain: Development with AWS Services

Original practice questions written by xOps School (DevOpsSchool Private Limited) from the public AWS exam objectives (DVA-C02 exam guide version 2.1 (2024-12-12); DVA-C03 announced, DVA-C02 available until 2026-11-30), checked 2026-10-25. They are not actual exam questions. xOps School is not affiliated with or endorsed by AWS; exam names are trademarks of their owners. Official exam page: aws.amazon.com/certification/certified-developer-associate/.

Last modified: Sunday, 25 October 2026, 9:57 PM