The first time I was emailed about conducting an initial phone conversation was around a month and a half after applying for the position. That phone conversation was your average phone interview, with most questions regarding my background, job interests, and experience. Right off the bat it was very clear that my interviewers (which I later found out were my manager and team leader) did not understand any of the technical information that I was giving them, despite the extremely technical nature of the position I was applying for. That phone conversation lasted roughly an hour and ended with the interviewers telling me that they'd like to interview me in person so that was obviously a good end to the interview.
The in-person interview happened about a month later, and was a mixture of one-on-one and group interviewing. For the first 20 minutes or so, they explain to you the complex structure of the company only to follow it with, "oh, you don't really need to understand this." Not really off to a good start...You end up meeting with at least 2 or 3 of the managers/directors/team leaders who all end up asking the same exact questions so be prepared to repeat yourself a lot. There was a short tour of the office and facilities and the opportunity to meet the primary people in your future group. Those group members also had a chance to interview you and, once again, ask the same questions over and over.
The whole in-person interview lasted about 2-3 hours. Luckily, they are quick to judgement after that, with an offer of employment in about 2 days. Don't expect any negotiation on salary, benefits, etc. though.
I'd say all in all, the interview process was a little long and drawn out, highly repetitive, but not too difficult to nail.