I applied through their website to be a Project Manager, got offered a phone screen and online assessment a few days later.
Phone screen was very straight forward. The interviewer didn't know a lot about about the position, and asked general questions about educational background (current college senior), if you did a gap year, willingness to travel/relocate, and a "Why Epic" question. The online skills assessment is self-scheduled and consists of questions on math, logic, and reading comprehension. Make sure you have a four-function calculator and scrap paper!
A few days after I got offered an on-site interview in Verona. They told me then they wanted me to interview for both the PM and TS roles. They will set you up with a flight and hotel for the day of your choosing. The day consists of them selling you on Epic, time to ask questions with a current employee(s) in the roles you are interviewing for, and then case-like interview questions for your role(s). For the PM position they have you give a 10 minute presentation on a topic of your choosing. There is a final interview with an HR representative where you go over start dates, your preference between roles, and other details. Everyone was very friendly and open. They will have a lot of candidates on sight interviewing for different roles in any given day.
Less than a week later they called with an offer for the TS role, and not the PM. I have heard of other people being given multiple offers.