Found out about the position through a friend, was contacted by the HR person, came in expecting to talk to a couple of people, ended up talking to 8 (?) over the span of 3-ish hours, in a small meeting room, 1-2 people at a time, usually in person, but also sometimes over the phone in the room. Received a brief tour of the immediate office surroundings, was walked out by someone I interviewed with. Very pleasant, very helpful, very acknowledging of the fact that it was a long interview process.