A friend who's an engineer there passed my resume along. Had two phone interviews which I found quite difficult. They both had me code in collabedit.org, and the second also actually ran my code on codepad.org - that was a surprise! I did not do perfectly on the phone interview questions, but still got through. They brought me on-site for an interview day which included a tour, lunch, a talk, and four 1:1 interviews. One-half of the first interview included some questions about leadership, teamwork etc., and the rest were all technical. One of the interviewers seemed to be in a grumpy mood, but that's the luck of the draw. The whiteboard coding questions were not too bad and I think I got them all, though with some silly mistakes along the way. I'd agree with the previous reviewer who said their questions are not as difficult as Google's- though perhaps they therefore have higher expectations as to how quickly/flawlessly you solve them. On my way out they gave me a goodie bag with some swag. Oh, and at one point I saw Zuckerberg milling about. Got an email a week or so later- I would not be winning the Facebook IPO lottery!