"One of the biggest traps for smart engineers is optimizing something that shouldn't exist."
Elon Musk.
Elon Musk.
https://en.m.wikipedia.org/wiki/Monorepo
Then you can do your own opinion, I'm sharing mine.
In smaller scales, for example, they're fantastic for productivity, and my company is not looking back.
According to multi-repo advocates, it would obviously be split up into at least a dozen different repos, with dependency management tools to specify which version of zlib or ebpf to use, with a dedicated repo just for the build logic, of course.
But you can find a list on Wikipedia and make your own opinion : https://en.m.wikipedia.org/wiki/Monorepo