[Lvl999Noob]

The classic 0, 1, or N. You can have 0 repos (no-code or outsourced or just some unversioned blob of code). You can have 1 repo (a mono-repo). Or you can have N number of repos (individual micro services). Limiting yourself to a number that's higher than 1 but still finite is just asking for pain. (Of course implementation limits can apply but there shouldn't be logical limits)

[echelon]

Monorepo and microservices are orthogonal.

You can have as many build targets in a monorepo as you like. You can also have large monoliths in a monorepo.

[bvrmn]

I worked with monolith split into multiple repos as well. It's orthogonal indeed.