Some years ago after being laid off from one programming job, my old CS prof from college suggested I stop by to interview with the Epic recruiter who was visiting the campus. I was told to block out about four hours time, and that it would be a very in-depth technical interview. It turned out to be nothing of the sort: it was maybe ten minutes of talk with a human being, and hours and hours of filling out a badly-written "technical exam". Allegedly it involved seeing how well the taker could think about programming languages and programming language concepts by giving us a toy language to write a parser and compiler for, but ... holy toledo, was it a stinker.
First, the language was defined in plain English. There was no BNF. When ambiguities of English occurred (as they always do), the Epic rep was unable to give any resolution as to what the language was supposed to do. My protest of, "Well, if you don't know what it's supposed to do, how can you expect me to write a parser or compiler for it?" fell on deaf ears.
Second, certain mathematical operations were supposed to be supported ... but the language was vague: they were supposed to have their "conventional" meanings. But some mathematical operators are defined sort of vaguely: for instance, it's not really well-defined mathematically what the modulo of two negative numbers are. As a result, different programming languages tend to implement it differently. (For instance, C++03 says it's implementation-dependent, while C++11 has a strict policy on it.) How did they want the modulus operator implemented? They had no idea.
Ultimately, when it came to writing a parser and compiler for their toy language I decided to do it the right way as opposed to their way. Instead of having an ad-hoc thing, I turned the exam over and started writing a formal BNF and lex/yacc rules on the back of the pages. I took the full four hours to do the technical exam, turned it in, told them that my work was on the *back* of the exam and not the front, and walked out.
Six weeks later, not having heard a thing from Epic, I sent them a politely-worded email saying, "If I'm going to spend four hours on a Saturday on an interview for Epic, I would appreciate the courtesy of being told whether I would be receiving a job offer or not."
A week after that I received a one-line email: "We regret to say that we're going with other candidates."
Anyway. That's my experience with Epic. Take it for whatever it's worth. I didn't think much of their interview process, and they sure didn't think much of me.