API Gateway Pattern
Sits between the client apps and the microservices. It acts as a reverse proxy, routing requests from clients to services. It can also provide other cross-cutting features such as authentication, SSL termination, and cache.
External Configuration Store Pattern
Move configuration information out of the application deployment package to a centralized location.
Strangler Fig Pattern
Migrates a legacy system by gradually replacing specific pieces of functionality with new applications and services. As features from the legacy system are replaced, the new system eventually replaces all of the old system's features, strangling the old system and allowing you to decommission it.