I've really enjoyed taking the time to realllllyyy scratch itches and niches that I've been annoyed by for two decades. Things like, "I wish I could make a usable web-based tool for my programming language without badly implementing half of a usable text editor... again" https://typesafety.net/rob/blog/endless-sketchzone
(All things considered I'd prefer my job search to have panned out by now... 🙃 but even so... 🤷)