The interview process included a few layers: a technical test, a non-technical interview, and technical interviews.

They started with a phone interview verifying basic information, then brought me in for a fairly standard "can you actually program" written test. After that was a series of technical interviews (back to back) with different groups and technical managers.

They asked pretty standard questions, but were fairly specific about the languages I'd be working with, with some general optimization questions peppered in.

Asked a lot of language-specific questions: the best way to divide strings in various languages, the most optimized sorting methods, performance differences, etc.