Programmers are often taught that they should modularize their code, breaking it into small pieces so that each piece can be managed, maintained, and reused. But what if you went in the other direction, using a single codebase for everything — in your workgroup, your division, and even your entire company? That’s how Google works; in a given week, their code contains more changes than the total number of lines in the Linux kernel. In this talk, Rachel Potvin describes why Google works this way, and how they manage so many engineers, changes, and applications in a single, huge repository.  Even if you’ll never with so much code where you work, it’s definitely interesting to learn how Google manages its code, and the tradeoffs associated with this system.