DVA-C02 Exam Dumps - AWS Certified Developer - Associate

This solution is the most efficient method to grant users access to AWS resources without requiring them to log in. Amazon Cognito is a service that provides user sign-up, sign-in, and access control for web and mobile applications. Amazon Cognito identity pools support both authenticated and unauthenticated users. Unauthenticated users receive access to your AWS resources even if they aren’t logged in with any of your identity providers (IdPs). You can use Amazon Cognito to associate unauthenticated users with an IAM role that has limited access to resources, such as Amazon S3 buckets or DynamoDB tables. This degree of access is useful to display content to users before they log in or to allow them to perform certain actions without signing up. Using an identity provider to securely authenticate with the application will require users to log in, which does not meet the requirement. Creating an AWS Lambda function to create an IAM user when a user accesses the application will incur unnecessary costs and complexity, and may pose security risks if not implemented properly. Creating credentials using AWS KMS and applying them to users when using the application will also incur unnecessary costs and complexity, and may not provide fine-grained access control for resources.

Amazon CloudFront is a global content delivery network (CDN) designed to deliver static and streaming content with low latency and high throughput . AWS documentation explicitly recommends CloudFront for media streaming and high-request-rate workloads.

By placing CloudFront in front of Amazon S3, video content is cached at edge locations close to end users. This dramatically reduces latency, minimizes buffering, and offloads request volume from the S3 bucket. CloudFront is built to handle sudden traffic spikes and supports tens of thousands of requests per second per edge location.

Route 53 routing policies (Option A) control DNS resolution but do not cache content. Cross-Region Replication (Option B) improves regional availability but does not provide edge caching or streaming optimization. S3 Intelligent-Tiering (Option C) optimizes storage cost, not performance.

Therefore, using CloudFront with S3 as the origin provides the largest and most immediate performance improvement.

An Application Load Balancer can invoke Lambda functions as targets, but ALB must be explicitly granted permission to invoke the function. This is done by adding a resource-based permission to the Lambda function policy that allows the Elastic Load Balancing service principal to call lambda:InvokeFunction, typically scoped to the specific target group ARN.

If the developer registers the function as a target but does not add the required permission, the ALB will not be able to invoke the function when requests arrive. This is a common integration oversight: the target registration succeeds, but invocation fails because Lambda denies the call.

Option A is incorrect because ALB does support Lambda targets.

Option B is incorrect because Lambda targets can be configured through the console, CLI, or APIs.

Option D is unrelated: cross-zone load balancing affects distribution of traffic across AZs for instance/IP targets, not whether Lambda invocation is authorized.

Amazon SNS subscription filter policies are designed to control which messages are delivered to subscribers based on message attributes. AWS documentation recommends using subscription filters to reduce unnecessary downstream processing and cost.

By configuring a filter policy on the SNS subscription, only messages that match refund-specific attributes are sent to the Lambda function. This ensures that the Lambda function is invoked only when required , eliminating wasted invocations and simplifying the function logic.

Option A is incorrect because Lambda event filtering applies to services such as SQS and DynamoDB Streams, not directly to SNS. Option B increases invocation cost and code complexity. Option D does not filter messages and does not address the requirement.

Therefore, SNS subscription filter policies provide the cleanest, most efficient, and AWS-recommended solution.

In CodePipeline, the service designed to run builds, execute unit/integration tests, and produce build artifacts (including test reports) is AWS CodeBuild. CodeBuild runs commands specified in a buildspec.yml file and supports reporting outputs such as test results (for example, JUnit XML), code coverage, and other build metadata.

Option A is correct because the developer can configure the CodeBuild project to run the test suite during the build phase and configure the buildspec to publish test report files. This integrates naturally into CodePipeline as a build stage, and the reports are generated consistently on each pipeline execution.

Option B is incorrect: CodeDeploy is for deploying applications (in-place/blue-green) and lifecycle hooks, not for standard build/test report generation.

Option C increases operational overhead by managing an EC2 build server, which is unnecessary when CodeBuild provides managed build environments.

Option D is unrelated: CodeArtifact is a package repository, not a test reporting solution.

Therefore, use CodeBuild and configure test reports via the buildspec.

Amazon Q Developer (formerly part of CodeWhisperer) is an AI-powered assistant integrated into IDEs (like VS Code or JetBrains). It can generate unit tests, explain code, and suggest improvements. Highlighting a specific function and asking the agent to generate a unit test is the fastest, lowest-effort way for a developer to test a function before committing code, as it happens directly within the development workflow.