Very streamlined and pleasant interview process. Started off with a recruiter contact me to describe the position and gather my background. A phone interview was scheduled. The interviewer called and introduced himself and asked about my background. He then asked several high level iOS development question. Afterwards we used Colabedit to work on 2 algorithm problems. The problems were fairly straightforward and general preparation is sufficient. The interviewer did a great job talking through the problems with me and gently prodding along though sticking points.
About a week later I received an email stating I was invited to interview on site in San Fransisco. Driving at the office I was greeted and taken to my interview room. I was presented with a small gift bag of snacks and a welcome note on the white board which was a nice touch.
There were 6 interviews. Since this was for an iOS position it was nice to see that 2 of the interviews were actually iOS engineers who specifically focused on the platform. One was an algorithm interview consisting of 2 problems. Another was for system design, which involved designing an app and the corresponding api. There was a casual lunch interview, and finally a chat with the hiring manager.
Every person I spoke with was nice, helpful and generally pleasant. The experience was as pleasant as an interview gets.