Pros
Great company doing good for the greater good - not creating value for shareholder nor increase its own cash. There is a calling for your day to day job, and you can easily tell the difference you are making, think about MyChart or CareEverywhere, as a patient I cannot tell how happy I am when my providers are using them for me. Take care of its people seriously - the benefit plan, the pay, the campus, and the career building thru various education and professional developments.
Cons
There is a price when your mission is critical - stress has always been one thing I am aware of working at Epic - no matter your role SD/QA/TS/IS, you are at some point feeling panic attack. The structure of the company is flat, to the point you have a lot of decisions to make on your own, trust me, it was never easy. I had to make calls on big projects' directions and actually regretted later - and they are the reality in the products now. Hard to maintain a healthy work/life balance if you care about your work - you are very likely to overwork yourself one way or another - and most Epic people do care so they end up putting more than 45 hours into their work week including myself.