I first met with them at a school career fair, then an on-campus interview preceded by a meet-n-greet the night before. The meet-n-greet was very laid back at a hip local pub, and all the employees there were so friendly and willing to answer any questions about the following interview/company. The on campus interview was brief (~30 mins) and the questions were pretty standard, but don't be surprised if you get a kind of weird/funny question.
The second round of interviews is in-house at their Dallas headquarters. Overall, this was an awesome experience - you get to tour their office space, see where you'll be working if hired, and even speak with the CEO. This round is pretty intense, consisting of 3 rounds ("speed dating" interviews, presentations, and a Q&A panel w/ new hires). Like w/ the first round, there's a reception the night before, which is when you get to tour the office and hang out/talk with the employees in a casual setting before the big interview.
The whole recruiting process reminded me a bit of greek rush; very fast paced, exhausting, and exciting all at the same time. You talk to so many people and constantly need to be on your toes. Ask smart questions (about travel, the transition to moving to Dallas, about projects you may do, challenges on the job, etc.) and take lots of notes. They like to see that everyone is enthusiastic and engaged - like not only a good and intelligent worker, but also a fun, vibrant person who will fit the company culture.