After submitting an online application, I was contacted for a phone interview with one of their current TS employees. The purpose seemed to be mostly to tell me about the job rather than to evaluate me as a candidate. Then there were the online tests--the proctoring system is annoying, but the tests were not too hard. After that, they flew me out to Madison for a day of interviews -- there was a case study, an HR interview, a few tours of their campus, some presentations, etc. When they say dress casually, they mean it. I wore jeans and still got an offer.