Was called quite a while after applying and asked to come in for an interview. It was very lengthy overall, about 2 hours, and I interviewed separately with 3 people from different departments. The interviewers were all very nice. I was asked about my experience and some normal interview questions, I was also asked some kind of puzzle or riddle questions, such as one with two rooms and how to figure out which light switch turned on which light without seeing into the other room. I thought it went well but I was not offered the position.