Interview structure was two managers followed by a director. Mostly behavioral questions. I showed up at their office HQ in Boston where a recruiter brought me down to the interview room. Each section of the interview was about a half hour, so the total interview time was an hour and a half. The third interviewer (the director) I feel like was mostly a formality. He told me a little bit more about the company and made small talk, before he strongly hinted that I was going to get an offer.