[dfee]

My journey went through mypy, then typescript for frontend, the typescript on node. The story here was the type system is so much better that it allowed better prototyping, larger codebases and confidence.

I’ve done a lot of C# and Java now over the last few years, and I don’t love their type system, esp compared to typescript, but they scale much better against large codebases - especially with tooling like bazel.

I’ve been looking at Haskell and Rust a lot to fill this intermediary: code that’s performant, with a very expressive type system.

I maintain(ed) a number of popular python packages, and that journey lasted for nearly a decade.

[daxfohl]

This is my experience, having gone the route you're looking. Haskell (~6 month trial) was unproductive for me. Primarily the ecosystem is full of abandonware. Secondarily it lures you into spending way too much time refactoring stuff into the most concise possible form, which you can no longer understand (and frequently needs rewritten completely because the tiniest change to the most concise possible form invariably explodes through several layers when you have to make changes later). Rust (~3 month trial) may be great for codebases where you'd legitimately consider C / C++, but too much work otherwise; I personally wasn't doing anything that I'd use C for, so it was not worth it.

I ended up being very happy with F# as a middle ground for several years, but eventually migrated back to C# as they started adding more and more F# features. The primary challenge with F# was the parity mismatch with the underlying runtime, so you end up having to write a fair amount of non-idiomatic F# to interop with common libraries. But otherwise it's great. (I also tried Scala for a year and hated it: too many ways to do any one thing).