You can add another build step right after the `tsc -w` compilation phase, which takes your .ts files, parses them to find our your types, and emits runtime cod

You can add another build step right after the `tsc -w` compilation phase, which takes your .ts files, parses them to find our your types, and emits runtime code that checks your types. That's what you're describing that TypeScript should be doing on its own. But I don't see why you'd want to do this instead of using io-ts? This is more complicated overall.