Ever thought about how much code required to run the services of Google? Rachel Potvin, an engineering supervisor in the firm disclosed at a recent convention that was @Scale that it is in the area of two billion lines.

And it is all saved within a repository. Potvin thinks that it is the greatest code base in the world.

Google has crafted its own variant control system called Piper, to host its whole codebase and let its 25,000 programmers to give to it.