Wow, I really love that experiment. Really explains a lot about frameworks to me, despite being an exercise in not using them. Thank you so much for making that.

When I look at what you've written under those restrictions, the biggest problem I flag as a general software engineer is how the events get created, defined, listened to, etc. This tells me that if I was building something "large" like that, the first third-party library I'd want to integrate is something for handling those event streams in a more rigorous and robust fashion.