I guess JS doesn't have to care about this at all because they're not selling their UI to others, just making it in house for in house use
Think node, except the other direction. They write their backend in OCaml, and then they also write their web ui in OCaml with a translation layer
Or think of gwt (java) awhile back
I guess JS doesn't have to care about this at all because they're not selling their UI to others, just making it in house for in house use