Rustler doesn't get the notice it deserves. I see people talk about using Rust to extend Ruby and Python and Node all the time, but none of those value concurrency-safety as much as Erlang does, and in the domains people tend to use Erlang for, the difference between using C and using Rust for NIFs matters even more than in typical back-end serverland.
I have a feeling there are plenty of excellent NIFs for most situations so most people using Elixir haven't been very dependent on Rust optimizations. Especially the web people who usually don't need that level of optimization, unless you're a giant like Discord, which is relatively unique.
Although I wouldn't be surprised to see more and more of Rustler as both Elixir and Rust gain in popularity. There's probably plenty of low-hanging performance fruit for any future rustler devs.
