I applied through an employee referral. The process took 3 weeks. I interviewed at Meta (Menlo Park, CA) in May 2012
Interview
First step is one or two phone screens, then a half-day or more of on-site interviews. Focus is on programming and architecture talent, but they're also looking for a good cultural fit. An important thing is that you may be interviewed targeted for a specific function, or for general engineering qualifications. In any case, after boojtcamp, you will be shopped around to all the groups that are looking for people, and you get to call your shot, so you don't have to have your specific career path chosen before you apply.
Interview questions [1]
Question 1
Most challenging question was an exercise in designing a system to do spam detection work and describing it in a huge flowchart, as might be done in an early but detailed product planning session. Be prepared to think on large scales.
I applied online. The process took 2 weeks. I interviewed at Meta
Interview
Submitted my resume online, and got an email about two weeks later setting up a technical phone screen. It consisted of typical coding questions that you'll find in any book. The first round is pretty simple and they're just looking for basic coding skills. My advice is to be sure you have practiced with a compiler.