The process took 1 day. I interviewed at Meta in Jan 2009
Interview
I was contacted by Facebook after finishing several of their puzzles puzzles. The first round phone screen from HR was non-technical. The second round was from a software engineer. There was one technical coding question, and we shared an online doc to write the code. I didn't do well, and received a rejection letter a few days later.
The process took 1 day. I interviewed at Meta in Jan 2010
Interview
First round HR interviewed with one simple puzzle and Algorithm questions. Complexity of some sorting algorithms. If the questions are not answered properly, they will ask you to solve a puzzle and send it across.
The difficult puzzles from the link http://www.facebook.com/careers/puzzles.php
Meal and buffet questions.