I initially met some employees through a developer conference and they invited me to the office for lunch. I was very impressed with the culture and the employees and so they set me up for an initial "phone" interview. I work close by, so I went to the office rather than taking the interview over phone. The next week I came back for interviews from 8:30 to 1:30 with five different engineers on the web team and lunch with another member.
The questions were pretty typical for software engineer interviews. Some binary tree questions, array manipulation questions, and also some fun write your own version of some popular custom UI element questions. The interviews were each themed for Architecture, Platform Specific (Javascript), Algorithms, Problem Solving, and Culture Fit. I think it allowed good time for getting to know me as an interviewee.
The interviewers were really nice and helpful, and seemed happier than the typical I'm-Smarter-Than-You Silicon Valley interviewer. It was a breath of fresh air.