3 rounds: First round is a culture fit. The next two interviews assess your design thinking. You will do a live critque of a popular, non Facebook owned app. (I did Yelp). The final interview had me going very in depth about the strongest project in my portfolio. These last two interviews each lasted 45 minutes each (The last one went over a bit). Fantastic, friendly people. Ran out of spots for interns for the 2015 season, so my application is paused for the 2016 season.