It's a thousand times better than typical React or Next.js lectures~ and it's fun too. Above all, I doubt there's a lecture that explains the module system, one of the foundations of JS, more easily and deeply than this one. From the history and development process of module systems, from CJS, AMD, UMD to ESM, I was able to learn in detail why such methods emerged, including their implementation and specifications. The lecture style of deepening understanding by actually implementing it was also great. I'm very much looking forward to the next series :)