There was a 30 min phone interview with the head of UX. Then a 3.5 hour in-person interview consisting of a 1 hour portfolio presentation, and two 1 hour whiteboarding exercises. Then an additional interview with the CEO at a different date.
My only critique of the process is that I spent a great deal of time and energy to put together a 1 hour presentation and then complete 2 exhausting 1 hour whiteboarding sessions. At most companies the whiteboarding session is 20 minutes because it can be very stressful, and thus exhausting. But the frustrating thing was that after this experience I sent a very polite follow up to the design team and also an HR person and no one ever responded to my simple inquiry. I took a vacation day for this interview, I ended on a good note, and I understand that they may not have thought I was the best fit. But every candidate is also a person that spent 4 hours in your office and it would be nice to extend a thoughtful response to them after someon else has been chosen.