I've never worked for Google. But my understanding is that their deployment code doesn't really on any of those 2700+ repositories. I believe it doesn't rely on

I've never worked for Google. But my understanding is that their deployment code doesn't really on any of those 2700+ repositories. I believe it doesn't rely on anything that isn't checked into the monorepo. If they spin out an open-source project, they either (1) continue development internally and (maybe) do periodic releases by exporting that directory from the monorepo; or (2) allow development to occur externally and periodically import changes when upgrading the version used by the monorepo. Either way, the point is that to build any Google service, you checkout the monorepo and type whatever their equivalent of 'make' is. No external dependencies.