[globuous]

That's true, and I was impressed first time someone showed me that. But the cost of this luxury might not be worth it. Indeed, you mostly (only ?) communicate through an API. And if it's properly documented, which is now essentially automatic, you can easily generate your types from the frontend. To me, the cost of bringing JS to the backend dominates this luxury to the point where it's just not worth it. I'll just generate my types from the frontend and be done with it.