Now that I have calmed down a bit : , let me explain.
The contract is that the interface will change slowly—though the implementation underneath it could change.
Modern interfaces are RESTful APIs though there might be other API patterns, such as gRPC .
These APIs need API management
While pushing the responsibility of the interface to the service is the right model, there are many concerns that still need to be addressed around these APIs:
Be prepared to externalize
If one looks at API management for externalized services, these sound very similar.
Some API management capabilities like mediation, caching, OAuth, and deep traffic management might not be needed, since we should assume that the called services have clean APIs and are built to scale.
Equally importantly, treating every internal service as externalizable gives you business options you wouldn t have had otherwise.