A pipeline deploys the application to multiple Regions sequentially. You have Route 53 health checks based on CloudWatch alarms per Region. How do you ensure the pipeline waits to confirm a Region's application is healthy before moving to the next Region?

The correct answer uses AWS Step Functions to create a robust waiting mechanism. A Step Functions workflow can poll the CloudWatch alarm state, pausing execution until the alarm is in an OK state, or failing if it remains in ALARM for too long. Inserting this workflow as a pipeline stage between each regional deployment ensures that the pipeline only proceeds to the next Region after the current Region's application is confirmed healthy. Incorrect options: Using AWS CodeDeploy with automatic rollback is for deployment failures, not for waiting on a Route 53 health check based on a CloudWatch alarm before proceeding to the next region. A CloudWatch alarm action cannot directly pause a pipeline stage and wait for a state change; it can only trigger actions when a state changes. Installing the CloudWatch agent on EC2 instances is for collecting metrics, not for directly controlling pipeline flow based on Route 53 health checks. The pipeline needs an explicit mechanism to wait for the health check status.