Free AWS Certified Developer - Associate Practice Questions

Sample Practice Questions

Try these 10 sample questions from the AWS Certified Developer - Associate practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1An EventBridge event bus receives an order event that must invoke two independent processors in parallel. Which rule configuration supports this fanout?

   1. A. Create two event buses, each with one target.
   2. B. Create one matching rule with both processors as targets.
   3. C. Send the event twice to a rule with one target.
   4. D. Create one rule that invokes the processors sequentially.

   Answer: B

   Explanation: AWS states, "A single rule can send an event to multiple targets, which then run in parallel." A matching rule with two targets provides the requested fanout.

   Reference: Rules in Amazon EventBridge — Rules in Amazon EventBridge, opening paragraph

2. 2A web application needs a managed user directory for its users to sign up and sign in. Which Cognito component provides that directory?

   1. A. A user pool.
   2. B. An identity pool.
   3. C. An IAM permission boundary.
   4. D. An STS role session.

   Answer: A

   Explanation: AWS states, "An Amazon Cognito user pool is a user directory for web and mobile app authentication and authorization." It handles application user authentication.

   Reference: Authenticating users with Amazon Cognito user pools — Opening description

3. 3A Python Lambda .zip deployment includes lambda_function.py inside a nested src directory. Why might Lambda fail to run the handler?

   1. A. The handler file must be at the root of the .zip archive
   2. B. Python handler files must be inside a layer
   3. C. The handler file must be stored in an ECR image
   4. D. Lambda requires a requirements.txt file at the archive root

   Answer: A

   Explanation: AWS states, "If the .py file is not at the root of your .zip file, Lambda won't be able to run your code." The archive layout must expose the handler at its root.

   Reference: Working with .zip file archives for Python Lambda Event Functions — Creating a .zip deployment package with no dependencies, around lines 69-75

4. 4A direct Lambda Invoke request returns HTTP 200, but the caller reports a function-code failure. Which response detail confirms a function error?

   1. A. The X-Amz-Function-Error response header is present
   2. B. The Invoke response has HTTP status 200
   3. C. The ExecutedVersion response header identifies a version
   4. D. The LogResult field contains encoded execution logs

   Answer: A

   Explanation: AWS explains that when function code or the runtime returns an error, "the status code in the response from Lambda is 200 OK. The presence of an error in the response is indicated by a header named X-Amz-Function-Error." An HTTP 200 alone does not establish success.

   Reference: Troubleshoot execution issues in Lambda — Troubleshoot execution issues in Lambda, introductory error behavior, lines 24-31

5. 5An EventBridge rule should forward only events whose source and detail values meet specified criteria. What defines that selection?

   1. A. An event pattern on the rule.
   2. B. A target retry policy on the rule.
   3. C. A schedule expression on the rule.
   4. D. An input transformation on the target.

   Answer: A

   Explanation: AWS states, "Event patterns for event buses can match against the event source, event metadata, and/or event detail values." Thus the rule's event pattern selects the specified events.

   Reference: Amazon EventBridge event patterns — Event patterns for event buses

6. 6After users authenticate with an external identity provider, a mobile app needs temporary AWS credentials to access permitted AWS resources. Which Cognito component provides them?

   1. A. An identity pool.
   2. B. A user pool alone.
   3. C. An API Gateway stage.
   4. D. An IAM policy simulator.

   Answer: A

   Explanation: AWS states, "After users authenticate with their provider and present authorization to an identity pool, they get temporary AWS credentials." Permissions on those credentials control AWS service access.

   Reference: Getting started with Amazon Cognito identity pools — Opening description

7. 7A developer prepares a Python Lambda layer containing shared packages. Which top-level directory must its .zip file contain?

   1. A. python
   2. B. src
   3. C. packages
   4. D. site-packages

   Answer: A

   Explanation: AWS specifies, "Your .zip file must include a python directory at the root level." Lambda locates layer modules from that expected layout.

   Reference: Working with layers for Python Lambda Event Functions — Package your layer content, lines 33-40

8. 8A Lambda function runs, but its invocation logs are missing from CloudWatch Logs. What should the developer verify first?

   1. A. Whether the function execution role allows creating log streams and putting log events
   2. B. Whether the invoking principal can read the function's CloudWatch log group
   3. C. Whether the function resource policy allows CloudWatch Logs to invoke it
   4. D. Whether the log group's retention period is longer than the invocation

   Answer: A

   Explanation: AWS says "Your execution role needs the following permissions to upload logs to CloudWatch Logs:" and lists "logs:CreateLogStream" and "logs:PutLogEvents". Verify those permissions on the function execution role; permissions of the invoking principal do not upload function logs.

   Reference: Sending Lambda Event Function logs to CloudWatch Logs — Required IAM permissions, lines 24-35

9. 9A worker may still be processing an SQS message when another worker receives the same message. Which queue setting should the developer review first?

   1. A. The message retention period.
   2. B. The delivery delay.
   3. C. The visibility timeout.
   4. D. The receive batch size.

   Answer: C

   Explanation: AWS says, "If you don't delete it before the timeout expires, the message becomes visible again in the queue and can be retrieved by another consumer." A visibility timeout shorter than processing can produce the symptom.

   Reference: Amazon SQS visibility timeout — Setting and adjusting the visibility timeout

10. 10A backend API checks a Cognito user pool token to authorize an API operation. Which token is intended for this purpose?

    1. A. The access token.
    2. B. The ID token.
    3. C. The refresh token.
    4. D. An AWS access key ID.

    Answer: A

    Explanation: AWS states, "The purpose of the access token is to authorize API operations." An ID token describes identity, and a refresh token obtains new tokens rather than directly authorizing API operations.

    Reference: Understanding the access token — Opening description