[dullgiulio]

Not really. It's easier to make a single atomic breaking change to how different components talk to each other if they are in the same repository.

If they are in different repos, the change is not atomic and you need to version interfaces or keep backwards compatibility in some other way.

[pvg]

It's very much really. The fact that it's easier doesn't really matter - a repo is about access to the source code and its history with some degree of convenience. The process and policy of how you control actual change is quite orthogonal. You can have a single repo and enforce inter-module interfaces very strongly. You can have 20 repos and not enforce them at all. Same goes for builds, tests, history, etc. The underlying technology can influence the process but it doesn't make it.