Of course you're right in cases of a cold start. But if I understand the benchmark in the linked post correctly, the TTFB was measured assuming that the VM was

Of course you're right in cases of a cold start. But if I understand the benchmark in the linked post correctly, the TTFB was measured assuming that the VM was already hot & and the code optimized through TurboFan already. (Hence "assuming the function is hot.") Also, I don't see Rust + WASM on the linked benchmarks. WASM code still has to run in a VM and probably uses the Node.js runtime for syscalls. (Based on a quick search, it seems like most people compile to WASM and create Node bindings with wasm-bindgen.) Third, my claim isn't that JS can reach Rust+WASM speeds; just that it's not as slow as you might expect because you do have type information. Anyway, the whole point is moot because we're arguing over microsecond differences.