I think "web development" is too generic to say something like that. I'd consider a small data processing service, maybe a service invoked from the web server

I think "web development" is too generic to say something like that. I'd consider a small data processing service, maybe a service invoked from the web server you're already using in Ruby or whatever, is a perfectly pleasant place to use Rust, and often likely to be 1:1 identical to those other languages.