[lukasLansky]

I mostly agree. Just notes:

Classic example in favor of monorepos is shared internal library. You should be able to change its API in one step, because that's the way to not having to care about compatibility at all. Compatibility concerns only happen if there's a time difference and with atomic company-wide update, this just doesn't need to happen.

In my example, backend and frontend can be deployed together. And we can discuss whether they should -- I would say there is little benefit of maintaining such single-purpose, wide interface just for getting the ability deploy frontend changes only, but this would depend on care the team put into configuration of cluster orchestration.

Contract testing is good, but not as good as testing against the real thing. Very much depend on the circumstances though.