(one of the authors of Spin here.)

WIth the disclaimer that this is really early, and we don't have extensive benchmarks yet, there are a few things we are tracking for HTTP workloads (you can see the actual benchmark apps here — https://github.com/fermyon/spin/tree/main/crates/http/benche..., and the rendered results here — https://fermyon.github.io/spin-benchmarks/criterion/reports/):

- the response times — here are some benchmarks for requests that simulate 1 ms of work — https://fermyon.github.io/spin-benchmarks/criterion/reports/...

- the "cold" startup time — https://fermyon.github.io/spin-benchmarks/criterion/reports/...

Another disclaimer is that we have not focused on optimization work at all, so we expect to make significant improvements over the next few months.