I worked for 20 years as a software/hardware engineer and none of that stuff exists today or made a difference. Then I became a math teacher and built an introd

I worked for 20 years as a software/hardware engineer and none of that stuff exists today or made a difference. Then I became a math teacher and built an introductory Python curriculum, online Python IDE and graphics environment that I used to teach Python to about 200 kids over several years. I know for a fact it altered the path of several kids' lives, so I'd have to say that it was the most impactful things I ever built.