I believe teaching is underappreciated but has a very big impact. Teaching influences people directly.
If you have 80 hours or more to make impact sharing your skills in an awesome place look at https://docs.google.com/presentation/d/1Lgzn4eYqlAsWKGQXvk4E...
I'd suggest considering going back to tech/startups, but trying to join one that's doing positive innovation in an important cause, like edtech or online education.
See and I (personally) think that's the wrong way to go about it. Wouldn't it be arrogant for me to try to innovate education from the office of a startup? Shouldn't I be in the kids' world - letting actual experience guide the innovation? Using the scientific method to discover what works and what doesn't?
I'm glad you have the page in there, though! Best of luck with this project.
If you want to focus on education as a cause, then I agree working as a teacher at some point makes a lot of sense.
I think it'll be hard to work out what works just from that though, because the outcomes of education take many years and are often counterintuitive. You'd need to eventually do randomised controlled trials.