I had one 20 minute telephone interview before being called in for an in-person interview. For the in-person interview, I spoke with every manager in the department for 45 minutes each. The entire process took about five hours. Many of the same questions were asked several times between interviewers and I found myself repeating myself, often.
Note: If you are flying in to Seattle for the interview, be aware that the corporate headquarters is about 45 mins away without traffic, and possibly up to 2 hours with traffic, coming from SEATAC airport.