But don't conflate tough with what frustrates people. I spent 2-3 years designing and building 3D CAM software that presented MANY challenging problems from abstracting platform API's to optimzing toolpaths for cost effective manufaturing.

Not once did I get frustrated with the learning or implemention process. The frustration in a sr devs life (in my experience) usually comes from uper management putting "really cool" features on the back-burner to never be seen again.