So many great viewpoints here. Crystal for faster and concurrent Ruby. Crystal has a pretty advanced Web Framwork called Lucky not many know about. Haskell so good, but hard to convince people to use it for projects. Haskell also has a very advanced Web Framework called Integrated Haskell Platform. Scala's very impressive feature set. Zig is in such a super position and Julia is capable in so many ways including Fortran integration.
I'm surprised no one has mentioned Chapel or Nim though! My favorite programming speed benchmark is spectral norm and even though Chapel is the fourth fastest language (not benchmark) it's not using the forte of grid parallelism!
Nim is getting to be quite the monster and not beholden to Mega-Corps finance/steering like Python and Go are.
Also I want to add that Zig blows Rust away in many performances!
NOTE: Just as an ethical, solo, non-commercial Engineer, I sponsor Nim on Patreon and Zig on Github
Full Disclosure: It was me that downvoted preferences for Python and Go as the one language. One lang a low level scripting lang? Preposterous! LISP can do/be anything for example. Get out of here with that undercover marketing/influencer speak!