Had a phone interview followed by on site. Phone interview was good and the interviewer was very friendly. During onsite, I had about 5 one one one interviews. My interviews started on a bad note - the recruiter was late to pick me up from the lobby and my first interviewer came 10 minutes late. He then rushed me into a system design question. I outlined the initial design and checked with him if there were any specific directions he wanted to go into but got no response. I then kept working on the design question without him giving me any feedback. When there were only 5 minutes left, he started asking some questions on how some scenarios would work. I always thought that interviews were supposed to be a discussion rather than the candidate talking and other people listening but perhaps its different at Facebook. Other interviews were also average - my third interviewer was a girl who seemed too full of herself and kept being very sarcastic. My fourth interviewer hardly showed any interest in my thesis work though he was a very experienced guy so its possible, they are able to absorb everything without even listening.