cache-bust-deploy-validationlisted

# Cache-Bust Deploy Validation ## When to use Trigger this skill any time you are validating that a fresh deploy went live on a CDN-fronted host (Cloudflare Pages, Vercel, Netlify, Fastly, CloudFront, AWS S3+CF). Concrete triggers: - "Deploy completed but the live site shows the old version" - "Validating a deploy / verifying a feature shipped" - "Why is the new <feature> not visible?" - Writing a post-deploy smoke test ## The anti-pattern ```bash # WRONG — the CDN happily returns 200 with cached old content curl https://prod.example.com/page # looks fine, but is stale ``` A deploy can be **broken at the worker but green at the edge** for hours because the edge cache holds the last successful response. Validation that doesn't bypass the cache will report "all good" while real users are about to hit 404 / wrong content as soon as the cache expires. ## The correct validation loop ```bash # 1. Cache-bust on EVERY validation request curl -sS "https://prod.example.com/page?_=$(date +%s)" -o /tmp/fresh.html grep -c "<feature-marker>" /tmp/fresh.html # must be > 0 # 2. Inspect cache headers — Age > 60s on a path you just redeployed = stale curl -sS -I "https://prod.example.com/page" | grep -iE 'cache|age|x-vercel|cf-' # 3. Test the deploy preview URL too (each platform exposes one) — it # skips the production CDN cache layer entirely. # CF Pages: https://<deploy-hash>.<project>.pages.dev/<path> # Vercel: URL from `vercel ls` / deployment dashboard # Net