Long process - not uncommon for weeks to go by in between stages in the hiring process, but Epic has a top-notch HR department that stay is constant communication with you.
1. Applied online, had to take Rembrandt personality test, etc.
2. About 2 days later, was notified via email to set up a 30 phone interview with someone currently in TS. It took about 2 weeks to figure this out schedule-wise, but it's extremely easy as far as phone interviews are concerned. The guy went on about the position for a good 15 minutes, asked if I had any questions, to verify GPA/SATs, etc. Also asked about willingness to travel and relocate (say yes to both, and exaggerate travel).
3. Less than a week later, received notice to schedule a remotely proctored exam to assess my programming skills. Yes, the position explicitly doesn't require them, but they make everyone take the same test (even for non-technical positions), so just try your best. My test had to wait a good 2.5 weeks as I was in the midst of finals period when they contacted me, but try to schedule it ASAP. I have a decent amount of programming experience but was only able to answer 1/4 of the programming questions. I did think the 20 multiple choice questions regarding analysis of a contrived programming language were really easy though.
4. Even though I thought I did poorly on the programming test, I was invited to schedule an on-site interview about 2 weeks after taking the exam. Overall it was much easier, but more drawn out than similar "marathon type" interviews I've done at other tech companies. Everyone has a different schedule, but they started me out with a bunch of fluff (tour, product demo, Q&A with someone in the role you're applying for, and lunch), followed by the stuff that actually matters (TS interview, case study, GRE math and verbal - type testing, HR interview). While I appreciated the ability to ease into the process, I did feel that both my enthusiasm and eloquence waned as the day progressed, and would probably have preferred the fluff and substantive components of the day to be better staggered. It may have been different for the other candidates, though. Nothing was unexpected having read other reviews on this site, but I should note that lunch should not be regarded as an opportunity to kick back and relax. Frankly, that was my most uncomfortable portion of the day. I'm not sure whether you're actually evaluated during lunch, but the employee with whom I had the misfortune of dining seemed awfully judgmental and prying in his questions. Other people had completely different (more positive) experiences with the lunch, though, so take that as you will. Once the day's complete, they shuttle you back to the airport, and they're supposed to get back to you within a week.