Something I've realized in my life, whether professionally or in my own projects, is that the projects on which I most enjoy working are those which provide value by making the jobs or lives of others easier.
I enjoy working on utility projects, rather than novelty projects.
Utility projects, for me, are those that solve discreet problems for people. They are tools which make people's lives easier and don't rely on capturing attention, using algorithms to measure and optimize engagement. Solving real problems, and solving them well, should be all that is needed to drive engagement and satisfaction.
Utilities also have the potential to live longer than novelties. Utilities which add value for users never go out of fashion. When you are solving real problems experienced by real people, you're in the realm of utility rather than novelty.
In the past I would have said I enjoy building developer tools - tools to make the jobs of engineers better. My side projects like iota and rustbox are oriented towards developers. In recent years I've noticed that I have the same passion and enthusiasm in designing and building tools for our clients in Propylon, and that ultimately they are in the same category - not developer focused, but utilities. Solutions which make the jobs of real people easier.
Those are the problems I have found myself working to solve over the years, and at least for now, those are solutions I want to invest in moving forwards.