The process that I went through involved at least two phone interviews followed by spending more 6 hours in their offices for what I would consider a grilling by a team of uber-nerds with a superiority complex. They started off with a brief 1 on 1 interview at the office, followed by filling out a lot of forms (for about 30-45 minutes). Then they bring in their "team" of guys to interview you. This interview process was miserable.
They grilled me mostly on skills that I was not there to interview for. They guy that controlled most of the interview was an arrogant uber-nerd with a superiority complex that did everything he could to trip me up, including asking how to do something that you would never do and would never need to do for the position that they were seeking to hire (or any for that matter).
Some would argue that they were simply challenging my thinking skills, however it was obvious that the smug S.O.B. that asked the question was quite impressed with himself over it and was chomping at the bit to stump me. Though I did manage to get really close to the correct answer, having never had to answer a question remotely like that, I was satisfied to see him a little annoyed at how close I got.
For anyone whom wants to know, he asked me how to store an IP address in a 4-bit integer in PHP. There is no reason to ever do this. If you are that limited on space then you need better hardware. If you need to store it you store it in the database directly. That is sort of the original point of PHP, to run a site from a DB dynamically. The answer to the question involved bit shifting, which I haven't used since MIPS Assembler in college.
At the end of the day though, the bottom line was they were looking for an expert DBA, a Linux expert, a PHP expert, and a designer all rolled up into one person. They were not willing to pay what one of those positions was worth, let alone what all of those skills combined were worth. They were also looking for someone to work overtime every day a minimum of a half hour, but they "suggested" at least an hour, yet they didn't pay overtime (it was salary).
Several of the "team" members were just jerks from the word go and seemed to trying their hardest to one-up me in the interview. It was very stressful and after thinking about it, I just didn't have any desire to work there, ever. They tried to portray the place as a fun place to work with a few slick looking parts of the office, free soda, bi-weekly free lunches, and after hours free beer. But those "perks" didn't make it fun. They were bribes to make their slave labor look more willing and taken care of.
While in the interview I did make it a point to challenge them on the other reviews that they have had here on glassdoor.com (only after they had made me miserable for 5 hours). They didn't like that at all. If looks could kill I would not be writing this right now. The explanation they gave was straight from a P.R. handbook and they simply tried to say that some people "can't handle the fast paced environment" that they work in. It was a completely canned response with no decent followup to backup their statements.
If I was that stressed out in the interview I can't imagine how much it must suck to work there. You couldn't pay me enough to interview there again.