"Set nginx worker_processes to your core count"

"Set nginx worker_processes to your core count"
Half-right and outdated. Just use worker_processes auto; — it reads cores itself. The real bottleneck nobody mentions is worker_connections.
Default 768 means 1 vCPU caps at ~768 concurrent. Bump it:
— worker_connections 4096;
— worker_rlimit_nofile 8192;
Also raise the OS limit or nginx silently caps. One $5 vCPU served 8k concurrent for me after this.
Try it tonight.