Haskell is a great language for writing compilers! The end of our compilation pipeline is written in Haskell. Other stages are written in C++ (MLIR) and Python. I'd recommend anyone to look at Haskell if they have a compiler-shaped problem, for sure.

We also use Haskell on our infra team. Most of our CI infra is written in Haskell and Nix. Some of the chip itself was designed in Haskell (or maybe Bluespec, a Haskell-like language for chip design, I'm not sure).