The Numbers Don't Lie: FastCGI Still Outperforms at Scale After pushing 10,000 requests per second through three different PHP server configurations for 30 minutes straight, the results are clear: nginx with FastCGI remains the lowest-latency option for high-throughput reverse proxy workloads in 2026. PHP-FPM behind nginx comes within a few percent, while Caddy sacrifices roughly 30% throughput for operational simplicity—a tradeoff that makes sense below 5K req/sec but becomes costly beyond that. The Verdict: Performance vs. Simplicity If your workload is latency-sensitive and steady-state, FastCGI via nginx still delivers the best performance. The protocol’s minimal overhead and per-request efficiency matter more than most developers realize at scale. PHP-FPM behind nginx is functionally equivalent until you exceed 8,000 req/sec, at which point pool tuning becomes critical. Caddy shines for smaller sites, where automatic TLS, simpler configs, and reduced operational overhead justify the throughput penalty.…