App Engine Modules is a feature that lets developers factor large applications into logical components that can share stateful services and communicate in a secure fashion.
App Engine Modules (or just "Modules" hereafter) let developers factor large applications into logical components that can share stateful services and communicate in a secure fashion. A deployed module behaves like a microservice. By using multiple modules you can deploy your app as a set of microservices, which is a popular design pattern.