Looking For Advice on Finding A Problem to Solve

I've heard from various people about solving my own problems, but that's not the route I'd like to take. Anyone have any examples of founders reading online forums, finding a problem and building a company to solve that problem? This article seemed pretty good, but the person didn't seem to go past just doing the research: https://www.devwalks.com/lets-build-a-saas-startup-1/.