At one point Google and FB were trunk based monolithic repositories, and I haven't heard that has changed. If it has not, this might not be the best example for micro services leading to many repos.
https://talkpython.fm/episodes/show/16/python-at-netflix
Transcript: https://talkpython.fm/episodes/transcript/16/python-at-netfl...
> Today, Twitter is excited to announce participation in the first major release of the Pants open source project: 1.0.0, an open source build tool for monorepo-style source repositories.
They (for the most part) had two repos as of 11/2014. They certainly were moving towards one. Here's a public thread mentioning the two repos: science (mostly jobs, shared code) and birdcage (mostly services). https://groups.google.com/forum/#!topic/pants-devel/60Vzkole...