From an implementation standpoint, using that strategy is fairly easy. You can simply duplicate the work done so far with the Hello World application. Each internal service would have:

• A set of Ansible configuration
• A CloudFormation template (generated with troposphere)
• A pipeline in CodePipeline and an application entry in CodeDeploy

Your edge service would then connect to the other service through their ELB as shown in the following diagram and the communication would be done through a REST or remote procedure call (RPC) API:

The second option is to use the ALB.