Everybody will agree that big codebase need some sort of componentization so that understanding some part of the code doesn't require understanding the entire c

Everybody will agree that big codebase need some sort of componentization so that understanding some part of the code doesn't require understanding the entire codebase. I like multiple repos because it encourages that: having pieces of code that do not depend on each others, and having more well defined API. The speed gain of the tooling is just a side benefit.