Wishing for Rust support too. At the moment we are doing some batch processing stuff on AWS Lambda using Rust. We are wrapping the Rust binary in a Python script, which is fiddly and annoying.
if it's a "json" like data that is sent to you (i.e a structure made out of only primitive types and list/dict) it may be not that hard, but I think it will be a work with very few value outside of this very specific use case.
Have you head or Apex [0], from what I understand it just creates a node.js shim to call your binary, it's what I was planning to use.
Still really hoping we get direct Rust support at some point though.