> Cloudflare uses this extensively

Thanks for this mention - I found:

CloudFlare repos on GitHub using Lua: https://github.com/cloudflare?q=lua

Blog posts with "Lua" tag: https://blog.cloudflare.com/tag/lua/

Pushing Nginx to its limit with Lua - https://blog.cloudflare.com/pushing-nginx-to-its-limit-with-...

We make use of OpenResty and LuaJIT although we are moving away from them and more and more towards code written in Rust and other languages.