Create an Amazon Simple Notification Service (Amazon SNS) topic. Modify the BeginResponse Lambda function to publish to the SNS topic before the BeginResponse Lambda function finishes running. Subscribe all Lambda functions that need to invoke after the BeginResponse Lambda function runs to the SNS topic. Subscribe any new Lambda functions to the SNS topic.

Create an Amazon Simple Queue Service (Amazon SQS) queue for each Lambda function that needs to run after the BeginResponse Lambda function runs. Subscribe each Lambda function to its own SQS queue. Create an Amazon Simple Notification Service (Amazon SNS) topic. Subscribe each SQS queue to the SNS topic. Modify the BeginResponse function to publish to the SNS topic when it finishes running.

Create an Amazon Simple Queue Service (Amazon SQS) queue for each Lambda function that needs to run after the BeginResponse Lambda function runs. Subscribe the Lambda function to the SQS queue. Create an Amazon Simple Notification Service (Amazon SNS) topic for each SQS queue. Subscribe the SQS queues to the SNS topics. Modify the BeginResponse function to publish to the SNS topics when the function finishes running.

Create an AWS Step Functions Standard Workflow. Configure states in the workflow to invoke the Lambda functions sequentially. Create an Amazon Simple Notification Service (Amazon SNS) topic. Modify the BeginResponse Lambda function to publish to the SNS topic before the Lambda function finishes running. Create a new Lambda function that is subscribed to the SNS topic and that invokes the Step Functions workflow.