Cloudflare Workers is based on the Service Workers API, which is a W3C standard. StackPath looks like they are following this API too (though I haven't dug into

Cloudflare Workers is based on the Service Workers API, which is a W3C standard. StackPath looks like they are following this API too (though I haven't dug into their docs). So it ought to be possible to move code between these platforms. Hopefully others will follow suit as well. Fastly has gone a different route since they support WASM exclusively (no JavaScript), but I believe they are also following an open standard for the underlying APIs (WASI). (Disclosure: I'm the tech lead of Cloudflare Workers.)