Would be interesting to compare the two to Cloudflare’s new proxy [1] which they say will be open sourced soon. Their blog post suggests a significant boost in performance for connection reuse (not measured in this article) and resource utilization. On the other hand, Pingora seems much more specialized than Caddy or nginx.
[1] https://blog.cloudflare.com/how-we-built-pingora-the-proxy-t...