Teaching other developers. Maybe open a youtube channel for teaching programming, but for more senior techniques, i.e, how to build a robust software, approach to testing, error handling, logging, etc.
I debated starting a Youtube channel. I don't think I'm that special. I truly believe that what sets me apart is that I have good processes to get me working, asked a lot of questions to developers I admired as I was learning and read a lot of code to figure out how things work.
It would probably be cool to explain that to others. I enjoy talking about the developer mindset I possess when mentoring Jr Devs that cycle through with me.