Nice read, and beautiful website btw.

Nice animation on the maze building algo.

I remember trying to use Immutable.js back in the day. It's probably pretty great with Typescript these days, but I remember it was kinda hell with vanilla JS back then since I'd accidentally do things like assign `thing.foo = 42` instead of `thing.set('foo', 42)` and I'd comb through the code to see why it wouldn't work, and I remember not knowing when I had a JS object or a Record. All things fixed by Typescript, of course.

I'm slightly horrified by the memory leak that's casually introduced without even a remark as to the potential to cause a problem. I can't tell if I'm more horrified by the cavalier attitude or the fact that JavaScript makes having a global registry the only easy way to use an object of an arbitrary type as a key to Map.

But at the very least, if you're going to memoize immutable values, please do it in a way that allows garbage collection. JavaScript has WeakRef and FinalizationRegistry. (Why it doesn't provide the obvious WeakCache built on those is a mystery, though.)

The issues won't be visible on a toy example like making mazes a few hundred elements across, but if you use these techniques on real problems, you absolutely need to cooperate with the garbage collector.