I built an online course catalog / aggregator many years ago. It's my first web project after learning how to code using courses from edX and Treehouse. My goal was to build something that I'd want to use myself. It's undergone a few iterations since then. The site gained initial traction on Reddit where I shared my experience learning and building in the r/learnprogramming subreddit. That was enough momentum to get me ranking on search engines. I eventually set up affiliate relationships with several of the major online course platforms. Although I've built a handful of apps using React, Vue, etc. this one's a classic Flask app using Jinja templating. There's just a few tiny JS scripts I wrote for basic interactivity (like updating the state of the "Save" button). Feedback is most welcome! https://opencourser.com