Hacker News Reader

They run Rust compiled to WebAssembly.

Sure, but what's the stack? Wasmer or something like that? I haven't bothered to look it up, for sure they've written about it.

Cloudflare Workers uses v8 under the hood afaik (which makes sense, since they are js-first).

Although they recently announced that Wasmer was being used in their 1.1.1.1 DNS (however, that has little to do with the Workers product I believe)