I filed a request in FB carrer page. I had 1 prescreening with someone from HR and 3 technical interviews over the phone.
1st interview was about programming. it took about 45 mins, the questions was fairly simple, they just want to make sure you are programmer.
2nd interview was about system administration, I can say it was really tough, it's started with some travail questions and ended with tough questions. Even though there were some hard questions but they weren't something out of the blue.
3rd interview was mostly about networking again there was nothing unanticipated.
By that time they asked me to flew to fly to Menlo Park for onsite interviews. they paid for all my expenses and SF is a beautiful city!
My interview starts at 12PM, I had 5 interviews onsite.
1st interview was mostly about System and Networking, they asked me to explain as much detail as it possible that what does happend when you run "telnet facebook.com 80" in bash. I broke down all the steps and talked about 45 mins about it.
We went for lunch
2nd interview was about System administration, the guy asked me lots of question that I don't recall, the only unexpected question was what would you do if you had 1000 new servers and want to make them functional, I gave him some ideas though.
3rd interview was about programming, again they just want to make sure you know how to program.
4th interview, there was a guy from another IT group. His main questions were about the way I communicate to with other groups and how I would solve the problems when there are people from other groups involve.
5th interviewer, I suppose he was manager of FB's SRO. He asked me some stuffs that I don't remember exactly but he wanted to know my attitudes and this kind of stuff.
FYI if you are worried about the interviews you can freely ask HR about it and they usually tell you what's the interview about and you could preparer for that.
