 Modify the Build Stage to Add a Test Action with a RunOrder Value of 2:

The build stage in AWS CodePipeline can have multiple actions. By adding a test action with a runOrder value of 2, the test action will execute after the initial build action completes.

 Use AWS CodeBuild as the Action Provider to Run Unit Tests:

AWS CodeBuild is a fully managed build service that compiles source code, runs tests, and produces software packages.

Using CodeBuild to run unit tests ensures that the tests are executed in a controlled environment and that only the code changes that pass the unit tests proceed to the deploy stage.

Example configuration in CodePipeline:

{

" name " : " BuildStage " ,

" actions " : [

{

" name " : " Build " ,

" actionTypeId " : {

" category " : " Build " ,

" owner " : " AWS " ,

" provider " : " CodeBuild " ,

" version " : " 1 "

},

" runOrder " : 1

},

{

" name " : " Test " ,

" actionTypeId " : {

" category " : " Test " ,

" owner " : " AWS " ,

" provider " : " CodeBuild " ,

" version " : " 1 "

},

" runOrder " : 2

}

]

}

By integrating the unit tests into the build stage and ensuring they run after the build process, the pipeline guarantees that only code changes passing all unit tests are deployed.

Having separate CodeArtifact repositories in dev and prod accounts provides clear isolation and control.

Repository policies can restrict dev repo access to developers.

EventBridge triggers pipelines to test and promote packages only if tests pass, ensuring safe deployment to production.

Using S3 (C and D) is not ideal for package management.

A single repo (A) complicates access and version control across accounts.

To achieve multi-Region high availability for a serverless API-based application, the architecture must be duplicated in the second Region and supported by a multi-Region data layer and appropriate DNS routing. Option A provides the required multi-Region data layer using DynamoDB global tables , which replicate data automatically and asynchronously between Regions. This allows reads and writes in either Region and prevents cross-Region latency bottlenecks.

Option C ensures that the compute components—API Gateway REST API and AWS Lambda functions—are deployed in both Regions. Each Region operates independently, providing true active-active redundancy and allowing Route 53 to route traffic directly to either Region without dependency on the other.

Option E selects Route 53 latency-based routing , which directs each user to the Region with the lowest round-trip latency. This meets the requirement to route traffic based on the Region providing the best response time rather than only providing active-passive failover.

Option D (failover routing) supports active-standby topologies, not active-active. Option B creates a global secondary index, which does not provide multi-Region replication. Option F (multivalue routing) distributes traffic randomly and does not account for latency or Region placement.

Thus, combining DynamoDB global tables, duplicated serverless architecture, and latency-based routing fully satisfies the requirements.