Ask HN: Back end analogue for Elm?

Hi, I am finding Elm to be an amazing technology for frontend​ development: I like the functional paradigm, type-checking, algebraic datatypes, but more than that, I love the reactive architecture. The functional reactive architecture with effects.

I am aware of a few Haskell web frameworks, but as far as I know they are not based on FRP.

Has anyone had any experience trying FRP on the backend with a ML-like type system?