I had two phone interviews, and then a half day on-site interview. It started with lunch and then progressed to back to back 30 minute interviews. Everyone was incredibly nice and kind. When I started to get flustered in one of my interviews because the questions were really tough, I stopped and retraced my steps. It seemed to go over well and it's totally okay for you to say "Wow, that's a hard question". I was also surprised at the dogs! I knew dogs were encouraged at work, but I was expected lots of small and toy sized dogs but I was way off the mark. I saw tons of big dogs. I was given an offer the week I interviewed. The HR/Recruiter I worked with was very straight forward, answered all my questions and was just in generally incredibly helpful.