Pros
I love the mission. As a software developer, I've been able to work on projects that help doctors and nurses who care for my friends and family across the US. That feels good. The work itself is mentally challenging. I've designed and coded projects on multiple platforms, each with different quirks and ways of doing things. Most of my work has been in Cache, SQL, and Python, but also exposure to lots of other areas. Some projects have been in completely new areas, others needed to integrate into a very established code base. Never boring, always learning. I like how Epic has developers also lead the design process. I lead the design process for projects that I'm also the lead developer for. That means I get to devote time to learning about a given domain and designing my project, and I know I'm personally on the hook for whatever I proposed in the design. There's a nice balance between heads down coding and research/design. The benefits are great, especially once you hit the 5 year mark. Epic does a great job hiring fast thinkers. I'm a "boomerang" (I left Epic and later returned). I didn't fully appreciate the speed and efficiency of the "normal" Epic staff member until I left. It's a great place to work with really intelligent co-workers who positively challenge each other to continually grow.
Cons
My complaints would only be solved by going into business for myself and being my own boss. I have no intention of doing that. No option to work from home for part of each week. I could be just as efficient (or more efficient) working from home, meeting-free, for 1 or 2 days each week. Some of our processes can be tedious or annoying. Some individuals can be hard to work with. But those are normal at any profession, in any job, unless you work for yourself. For me, the Pros far outweigh the Cons.