While there is pingora https://blog.cloudflare.com/how-we-built-pingora-the-proxy-t..., I would recommend checking out envoy. Although not rust based, envoy has gained quite the repute for being extremely versatile and robust.
I'm interested in the space, but until they have automatic certificate management and middleware for managing DNS records in Cloudflare (for example), then I'm reluctant to switch over.