[arter4]

Probably yes.

You can scale horizontally with a lot of web servers and load balance them. You don't need to stretch load balancer clusters across AZs/regions, so I see no reason why Nginx wouldn't work.

I assume at that scale session cookies are shared without application server clustering. A distributed KV store is probably enough.

[donboscow]

Hi, I thought so too. But then why did it not work for Cloudflare, and why did their custom solution work with Pingora?

[arter4]

As it turns out, they didn't like that each requests lands on a single worker and can only reuse connections on that worker, which gets worse as the number of workers per server increases. Presumably, scaling horizontally wasn't cost efficient enough.

They also wanted something written in a memory-safe language so it could be extended without easily falling into memory safety issues. NGINX is written in C.