You have a fair point about plow. I've used it enough to know that it basically works at spamming HTTP requests at a specified concurrency. When I'm doing something where I want better accuracy I've tended to use K6 and Vegeta.

> Yeah, but, unless `plow` actually follows that redirect, it's not really measuring the actual end-to-end latency...

Not in this case, since the purpose here was to measure the POST (write) not the subsequent GET (read) that a browser would do after the redirect.