The 1st round was a 1:1 interview on campus that was set up following an information session about the company. It involved mostly resume-based discussion, and was not particularly stressful or difficult.
For the 2nd round, I traveled to the corporate HQ in Warsaw, IN several weeks later. They put us up in a local hotel. Numerous candidates were given a tour of the facilities, and then we had four sequential 1:1 behavioral interviews with HR staff and upper management. These were more difficult than the previous interviews, but I thought 3 of the 4 were of expected difficulty.