The fallacy of the database as an application tier is only equated by the folly of using it as an integration platform. Both approaches create a paramount technical debt that takes many years to pay, if it is ever paid. Why? Because both approaches lack the abstraction layer that you need to create loosely coupled systems. Why again? Because both approaches preclude any sound testing strategy.
I have already talked about what I think are valid use cases for stored procedures. You do not need to believe me. Check what my colleague Tim has to say about it. And you do not need to believe him either, but at least read what Neal Ford says about it.
If you are still not convinced, then I have for you the perfect shape for your diagrams:
