When discussing server side web dev, I think the most important aspect is the ecosystem and libraries/frameworks available as much as the language itself.
> Rust, Kotlin, Swift, ReasonML/ReScript/OCaml, Haskell, Elm or Clojure?
OCaml is an excellent language depending on what you are intending to do. I can't imagine though that it would be a pleasant generic server side.
The same would apply to most languages on your list, except perhaps Clojure who has an excellent ecosystem thanks to the JVM. But then, is Clojure a good webdev language ? maybe ? I only toyed with it for a very short time, but I don't see it on par with PHP or ruby for instance.
> Rust, Kotlin, Swift, ReasonML/ReScript/OCaml, Haskell, Elm or Clojure?
OCaml is an excellent language depending on what you are intending to do. I can't imagine though that it would be a pleasant generic server side.
From a very quick search, it looks like to even connect to Postgres you'd have to manage yourself the connection pools ? https://medium.com/@bobbypriambodo/interfacing-ocaml-and-pos...
The same would apply to most languages on your list, except perhaps Clojure who has an excellent ecosystem thanks to the JVM. But then, is Clojure a good webdev language ? maybe ? I only toyed with it for a very short time, but I don't see it on par with PHP or ruby for instance.