I had a good interview process at the beginning where the recruiter called me and responded to any questions I had. Had 2 phone interviews. The first one was okay, asked about some recent technology events and talked a bit about a specific technology. The second interview was strange - didn't feel like it tested my skills at all. The discussion was quite preliminary, and it was hard to exceed expectations when the questions were quite straight forward. At the end, I felt like I didn't have a great vibe with the interviewer, and I did not move forward in the process. What's disappointing is that this is really about fit and getting along with your interviewer, and that's hard to evaluate properly when you only talk for 20-30 minutes on the phone. Alas, this is the reality of most interviews and sometimes it's not all within your control. Definitely seems like an interesting company though, and the interviewers were friendly - would probably reapply again.

Phone interview -> in person interview -> in person interview -> founder interview. Standard non-programmer tech questions. Less focus on brain teasers and more focus on reading and understanding data (they brought in papers with charts for me to read and interpret). The (last) founder interview actually has a fairly low pass through rate, so don't think that meeting the founder = offer. Only problem was entire process lasted a few months for me - you need to stay on top of the recruiting department (through your referrer most likely) to keep the process moving quickly.