> However having worked with Typescript for 8 years now... I'm not sure I could go back to Ruby without types.

Very true for me as well. I've never worked with Ruby but feel the same way about Django.

Btw, if you're looking for a "Rails but with TypeScript," my colleagues and I are working on almost just that: https://wasp.sh/.

The main difference, besides the ecosystem, is that we're more in the "configuration over convention" camp. Wasp has a simple DSL for specifying said configuration, but it's about to be replaced with a TypeScript file.

Wasp is still in beta and nowhere near Rails-level polish. But, depending on your early adopter tendencies, you might find it interesting regardless. If you do try it out, please reach out and share your thoughts.