It surprised me that the first-round interview was with the president of the company, but it was a great way to get a read on the culture of the organization. Second round interview was with two current employees who did similar work to the position I was applying for, which was great insight into what daily life would be like. Third round was with the executive directors I would be working for, and they were able to answer any questions about the specific clients I would be working for.
Something I may have appreciated the most out of the entire process, though, was I think I heard back about if I was moving on to the next round within 24 hours each time. I've had so many other employers jerk me around and make me wait for weeks at a time just to find out if I was moving on, then another week or more to actually get in to do the next round. The speed and transparency at RGI was a refreshing change of pace.