Met with a developer and manager in a meeting room. Pretty relaxed, they offered me a snack or water, but also slightly disorganized since they weren't really sure if they had a room to do the interview. Discussed some of my experience from my resume, then proceeded to a technical question.
The technical question didn't really seem to have an answer, but it was more of a discussion of how broke down the problem, and what additional information you would need to solve the problem.
I exchanged emails after the interview with the manager further discussing the technical question. Eventually decided to go with a higher offer for another company.