There were about 5 interviews total over about 2 months. The first 3 interviews were at the search firm's office and each one was different, though we reviewed my portfolio and experiences mostly. The final interview was at their HQ outside Boston. They booked my travel and accommodations which made things pretty easy. Upon arrival I met the head of HR, who was very personable and approachable, and really made the whole experience pleasant. She gave me a tour of the grounds and also reserved a conference room for me where I could work between my meetings. Then I interviewed with the CEO.