@Ninjatrappeur I wasn’t aware of it (there were more typed nix initiatives in the past but I didn’t pay attention cuz I think DSL approach is a mistake).
I’d love to have Typed Guile in Guix (or even Guix-like *e*DSL but in Haskell/OCaml) and we are not alone in that desire https://github.com/taktoa/typed-guile/blob/master/Roadmap.rst
Though I didn’t investigate this area yet. A pure source bootstrap is more important to me today than benefits of a proper type system https://gitlab.com/janneke/mes
Of course having both would be ideal.