Google's codebase is ludicrously huge for good reason
 

Google's codebase -- the programming instructions that run every one of its services from Gmail to Slides -- span a whopping 2 billion lines of code that stretch across 1 billion files and require 86 terabytes of storage, according to Google engine...

http://www.engadget.com/2015/09/18/g...r-good-reason/