The interview process consisted of an HR phone screen, a technical phone screen, and, since I passed the technical screen, an on-site one-on-one interview with 5 separate people. I was given an itinerary of how the interviews were to go, but it was totally wrong.
During the course of the interviews, I had to do 3 white board tests, 2 of which were coding and one was test coverage related.
I felt that all interviewers were engaged in the interview and not just going through the motions as some have said on this site. Everyone was friendly. Most interviewers had worked there less than a year (some only 3 or 4 months). Several commented on the fact that I was wearing a suit to the interview, which I'm not sure if they were indifferent to it or it was a bad thing (evidently, no one in Austin wears suits to interviews). Not sure if I was being judged to "not fit in" with the culture due to my interview appearance. They seem to be very big on fitting in with their "culture". I am used to working for companies with very friendly and family like culture and have even worked at Startups before with a similar atmosphere as Bazaarvoice. You can tell they still operate like a Startup, including the long hours (that's why they have the free snacks and all).
Overall, I thought the interviews went well, although I know I could have done better in some areas. In the end, I did not get an offer. Honestly, after the interviews, seeing their offices, and reading comments on here, I was still very much on the fence if I would accept an offer; it would had to have been a really good offer. I already have a good job in a non-startup company with one of the best cultures I have ever worked in.