I originally applied for the Project Manager position. I heard back the morning after I sent in my application. Epic asked me to, within the next 24 hours, book a 2-hour skills assessment and take it within the next 5 days. The exam is proctored via Examity. You need to find a quiet, closed room, use a clear desk and show them your ID on the webcam. The test is four parts. The first part is rapid-fire math questions that you have ~2 minutes to answer. (Don’t expect to finish them.) You can use a non-graphing calculator and scrap paper as long as it has nothing on either side. The second involves learning a coding language and tests your ability to learn. They grade you on accuracy and speed, but there's no major reason to rush. No coding experience required. The third part was another rapid-fire logic, similar to standardized test questions. The fourth was a mix of reading comprehension, math, and reading charts and graphs, also similar to standardized tests.
I also had to do a personality assessment that took ~30 min and schedule a phone interview. The phone interview was short (~15 min) and pretty typical. They’ll offer to tell you more about the role at the end.
I heard back the next day and was asked to interview on-site for the Technical Solutions Engineer position. I asked to hear more about the role before committing to flying all the way up to Madison since it wasn't the role I originally applied for. They told me they'd be happy to tell me more about the role, in Madison.
I also had to do a programming assessment (LeetCode style) before, after, or during the on-site interview (my choice). I did it before the interview via Examity. I gave myself an hour and a half and didn't have time to finish unfortunately, as it was pretty challenging. Supposedly the exam is used to determine how much training you'll need if you do get accepted. You can use any language or pseudocode.
For the on-site interview, everything is taken care of by Epic and they’ll reimburse almost everything but alcohol and souvenirs. They try to fly you in mid-day the day before the interview to give you a chance to explore Madison and participate in a group dinner with other candidates and a current employee. The hotels they use provides complimentary breakfast and they’ll book a taxi to Epic with other candidates that'll get there around 8/9/10 depending on when you need to leave. There's an intro session where they tell you why you should work at Epic and demo their software for you. Then you and a few other candidates get to talk with someone in the role you’re applying for. (They have plenty to talk about if you don't come with many questions.) I then had a case study interview in which I had to read about three different client requests and determine which ones were most important and why, and then was asked how I would respond to certain client reactions or other problems with your team and your project. There really isn't a way to prepare for this, but I found it pretty easy. Then another current employee showed me and a few other candidates a video about Madison and took us to lunch in their cafeteria. (They're accommodating to most dietary restrictions.) Then another employee took us on a walking tour of campus (we stayed indoors). At the very end, I had an interview with HR that was pretty casual. (This, strangely, was the first time I had the chance to talk directly with HR in the whole process.) They asked what I liked and didn't like so far, and also asked me details about other offers I had (position, salary, etc.). Starting salary as of 2019 is $66k during training and $68k after, and they'll ask you if that's ok.
Overall it was a pretty easy interview - at no point did I really have to talk in-depth about myself and my experiences beyond a simple"why do you want to work here?/why are you a good fit for this role?", nor did I need to do a lot of research on the company since they told me just about everything, though it helped a bit. It seems that you're mostly evaluated on your skills assessments, but they're also looking for other qualities throughout the process -- e.g. willingness to stick around in the long-term, willingness to learn, willingness to put in many hours in a single week, holding themselves to a high standard (your grades will probably be the best indication of this), etc. There's a lot to like about the company (the philanthropy and service they do, their benefits package, the laid-back culture), but the TS role didn't have much to do with what I wanted to do in the long-term, and I didn't think I'd like the work enough to be happy with being expected to work as much as I was. r/epicsystems on Reddit is a fantastic resource for more interview advice and some less-filtered reviews of the company.