[jjgreen]

I've seen this and it works rather well in that one can have per-language bottom level build setup (with autoconf for C, setuptools for Python, ...).

[gen220]

I agree with the GP that it seems weird, and with you that it has its benefits. Of course, other approaches have their own benefits.

Personally, I feel like the top-level directory ordering for a monorepo is somewhat arbitrary, in that you can argue for anything, but it probably doesn’t matter; especially if you have a decent build tool.