Pros
There are interesting things to see and learn at Epic. You will probably make friends working there. I'm reaching hard to think of these pros, though.
Cons
The company's leadership actively (illegally) discourages employees from comparing salaries, which is incredibly suspicious when male employees tend to live on the isthmus in Madison and female employees generally live in cheaper flats elsewhere, with even more marginalized employees living in neighborhoods one could describe as poor. I was not able to get any accommodation for disabilities during training, and not being able to complete the training without accommodations I needed was ultimately why I was pushed out of the company so quickly. Epic has a reputation among former employees for its terrible work/life balance and its habit of grabbing new developers out of college, sucking them dry, and leaving them burnt out soon after with experience they may have trouble using elsewhere. There is no management to speak of, thanks to Epic's relatively horizontal structure. They make it sound like a great idea at first, but then you find out you're answering to someone who became a supervisor on technical merit alone and has exactly zero formal training in management or supervision. My own supervisor, for example, tried to solve late work from their team by making everyone do more and more meetings and time management exercises, which caused even less work to actually get done.