(have we come to some max nesting level here, cant reply to the child comment)

One db can be a problem, or a strenght depending on the domain; And I really dislike religious design, esp microservices.

I have less problems by avoiding ORMs (and religios microservice arch, or fundamentalist interpretations of rest)

Database handles the shared state in a heterogenous environment. We need it to be centralized to keep track of money, the apps can't do that, two independent databases cant do that either. It must be one system that guarantees concistency.

It works great, there is no downtime. The interfaces are defined, the database stands alone, updates are deployed separately.