Two day interview process at the corporate HQ. They paid for travel expenses. Consisted of a company tour and then interviews with several possible team leaders. The leadership not only is the manager but also knows the work the employees do which was a huge plus. Same group of people asked general behavioral questions as well as technical questions.
Knew within a month if I was accepted. Far as I was informed, they only hired from the internship pool, which I was a part of at that time, and do very, very few external hires.
Best interview process I ever had in the Chicagoland area.