Beyond the technical constraints, there's just the domain itself. I've focused my efforts in this domain of just digitizing paper processes. There's so much to know from a regulation standpoint and a quirky middle man chain standpoint.
Some of my proudest accomplishments in my career is just standing anything up that replaces paper even partially. I've been praised many times for just making something that works after so many have failed. None of what I did was technical amazing. A lot of what I did was just doing a lot of reading and talking to people and I'm amazed how many engineers weren't doing that.