Had asked my friend to refer, within a week was contacted by recruiter and was asked for dates for telephonic screen. Provided my date preference, and within 2 days the phone screen was scheduled. Got result of phone screen next day, and was invited to Facebook HQ for a day long interview. Facebook has University Day, where they call people and conduct their interviews, also on the same day they have campus tour with tech talk. But, as I had other offer deadline, they were pretty comfortable in scheduling "one-off" interview for me, and was called on non-university day just for the interviews.
Interview process was awesome. Had total of 4 rounds (1 Behavioral and 3 technical). Also after first round, I was accompanied by Facebook Engineer for lunch, and he walked me over the campus. I loved the campus and the interaction with the engineer. He almost answered all my questions and further gave me reasons about why working at Facebook was awesome. Post lunch, had 3 back to back technical interviews. All the interviewers were smart, provided enough information about the problem and also left grey areas for me to ask and figure out. For all the questions, implementation was expected. Most of the time during my interviews, I was standing and writing/discussing code on the white board. Overall the day was hectic but it is indeed great fun as I got pretty interesting problems to solve and discuss.
After the interviews, I got my result after a week.
Summarize: Fast and Fair Process. Great experience.