I'm working on custom integrations tailored to specific project so for me each project is like a new job where I'm picking up tools and technologies that will deliver stable and maintainable outcome. New job, new people and new challenges - that keeps me sorta away from burning out. So I guess the main question is how much influence do you want to have? Do you want to craft specific algorithm that is somebody else idea? Or do you want to come up with your own ideas and bring them alive? I'm in second group.