I had phone screens with the recruiter and hiring manager before being brought in a couple of times for in-person interviews - because they were in a hiring blitz, they had difficulty scheduling. While this was going on, I spent a considerable amount of time working with their product, going so far as to log bugs.
Generally, the interviews went pretty well. There were several people with whom I had instant rapport. One person who was excessively rude, which I now understand is a test of how one deals with rude people. The hiring manager was not much of a people person, and we didn't hit it off.
Overall, looks like an interesting place.