Awesome, thanks for detailing the thought flow and choices that led you here. I chose not to go the QuickJS route for performance reasons but I think it's a solid choice depending on the use case.

> They run in the browser as I understand, so fundamentally different

Yes, runs entirely in the browser, while this is a hosted product. StackBlitz technology is really good but it is closed source.

Yeah I was surprised by this when I opened their website.

Your setup - Rust/WASM kernel + Service worker - sounds really sweet. If already public, please do share the link, else looking forward to your launch!