I applied online and had two technical phone calls. One of these was on Skype, where the interviewer had me code something (described below).

After that, they flew me in for a day of interviews at their San Francisco office.

On the interview day itself, I started with a coding problem. The next interview was a design and architecture problem. These were the most technical components of the interview process.

After that, I had a brief behavioral interview with a team manager. They pair you up with a lunch buddy if you're around for lunchtime (I had a morning interview).

For my last interview, they had me find a bug in an open-source project.

How would you design and architect a system that developers can use to run validity/correctness checks in production? (involved coding it as well)

Implement a key-value store with history (through timestamps).

Given a bug report (on a private GitHub repo they invite you to), clone the project and try to find the bug and fix it.

(Skype + screen share coding problem) Implement a system to keep track of, allocate, and deallocate server names.