Some people are asking what these 4M lines of code are doing.
It's not gstack; I actually left off gstack in my LOC count since it's technically a Garry Tan project, not a YC one! The LOC count would be much higher if you included gstack and gbrain.
The vast majority of the codebase is internal tools for YC founders and for us to run YC. If you're not a YC founder, you won't have seen these, but we have built a ton of software for YC founders.
A small amount of it is public facing, like our jobs website Over the next year we're going to make a lot more of it public-facing and it'll be more clear why we're building all this.