Solution:

The high TTFB and edge→origin latency on us‑east4 is caused by Cloudflare’s proxy path to Railway’s edge. Railway staff confirmed Cloudflare is currently routing incorrectly to Railway, adding 300–700ms+ latency even when your app responds in <25ms.

Fix: Disable Cloudflare proxy (orange → grey cloud). Keep DNS-only mode.

After disabling the proxy, users consistently report TTFB dropping from 500–700ms to <30ms.

Railway continues to handle SSL termination even with Cloudflare disabled.

This is a known issue and Railway is working on their edge offering, but for now the recommended configuration is DNS-only Cloudflare.