It depends on which team you interview for. There are two or three teams that are led by different people. The Python development teams tend to use whiteboard questions and puzzles in their interviews. The Ruby/Rails team does not. The interview consisted of a 90 minute interview with the team lead and various members of the team. The Rails team seems more concerned with personality and culture fit than they are about skills, though both seem important to them. I hired on with the Rails team and they are awesome.