Comment by pupskipper

I've been working on a website monitoring service written in Rust. I had to port from using the reqwest library to libcurl in order to properly capture DNS/connect/TLS/first-byte timing. I basically ran the new engine side by side with the original for a few weeks, running 100k+ checks daily to get a 99.8% agreement. The mismatches were interesting because of the Cloudflare challenge that returned 403 based on the http/2 fingerprint, no matter the user-agent used.