Hello! I'm on the team that implemented this. I'll be writing a longer post on the design considerations and implementation details, but roughly - rust wasn't a good case for something that was mostly held back by i/o to the edge; further, the actual cpu/mem intensive part was handed off to webpack which was written in javascript. So wrangler v2 flips that design around, using typescript for the outer shell, which makes it easier for our users and community to contribute to the tool, and esbuild for the core part of parsing/bundling code (we may switch esbuild to a rust based bundler like swc in the future).

At $DAYJOB I need to set up demos of a system that provides a dynamic UI to provision various products. The system can emit webhooks for validation of incoming parameters (email, address, etc). With CF workers and almost zero prior knowledge of JS I was able to set up a working validation endpoint in about an hour.

CF provides a very neat way to route requests to subdomains to specific workers and terminates SSL, which was perfect for my use-case.