> It's worth noting that Cloudflare/AWS Lambda don't have per-request isolation and that's pretty important for server side rendering use cases where code was initially written with client side assumptions.

It wasn’t just because of SSR. There’s numerous opportunities for security vulnerabilities because of request confusion in global state. Per request isolation is definitely something Cloudflare would enable if they had a viable solution from that perspective. As such it’s irrelevant the language you write it in - Rust is as equally vulnerable to this problem as JS or anything else.

> If you don't then deploying a container to AWS Lambda or GCP Cloud Run is already pretty easy

Yea, but cloud functions like your talking about are best for running at the edge as close to the user as possible, not for traditional centralized servers. It also promotes a very different programming paradigm that when you fit into it is significantly cheaper to run and maintain because you can decompose your service.

> It might be possible to offer better cold start performance with the TinyKVM approach, but that is still an unknown.

https://blog.cloudflare.com/eliminating-cold-starts-with-clo...

You’d want to start prewarming an instance to be ready to handle the request when a TLS connection for a function comes in.