A minimal, production-ready way to run an Express app on Cloud Run: the Dockerfile, reading PORT, a deploy script in package.json, scaling to zero with a small memory limit, and the mistakes that cost the first hour.
How Cloud Run bills a low-traffic Node.js site, why min-instances 0 keeps it near zero, what a cold start costs you in latency, how memory and max-instances settings change the bill, and the small charges people forget: image storage, egress and the build.
On Cloud Run, a request to exactly /healthz is answered by Google's front end with its own 404 and never reaches your app, while /healthz/ and /health work. How to tell an edge 404 from an app 404 using response headers, and a naming convention that avoids the trap.
How to map your own domain to a Cloud Run service when DNS lives on Cloudflare: verify the domain with Google, create the mapping, add the A and AAAA records and the www CNAME as DNS-only, and wait for the managed certificate without breaking it with the Cloudflare proxy.