So Lambda & (L@Edge) is a general purpose computing system. They run a normal process in a programming language of your choice, then feed it event data, take the response out and continue the pipeline. They might keep the process running for reuse sometimes. If your process is being reused, it’s “warm” and works as fast your code. If it’s “cold”, your process start time, Lambda finding an execution slot, downloading your code there etc all add up. Good news is that if you’re doing multi core stuff or specialized code it’ll work fine (now including special Intel AV-something instructions).

Cloudflare workers took a different approach - they run V8 node-ish processes on all their edges, and you submit your code as JS or WASM that fits their interface (which is based on the service worker standard). They then execute it as a V8 isolate, which is blazing fast because the V8 process is already up and running, it’s just running JS/WASM code, which it knows how to do pretty well. Even the cold start is pretty small, because the JS/WASM tends to be pretty small and Cloudflare knows how to cache stuff.

They’re both very different systems, but both have their uses.