It's as everyone describes below. A day long affair from one interviewer to the next. They reached out to me, got the phone interview that same day, and was offered an in-person the following week. I had a fun time. The staff was extremely friendly and the interviewers were very enjoyable to talk to. They really want to get to know you and how your brain works so they ask you thought provoking questions meant to see your thought processes. They offer a very competitive salary and benefits, so they obviously want somebody who is capable of handling and thinking through challenging issues and tasks.