CDN cache invalidation: purging stale content after deployments

After deploying new static assets or content, users continue to receive cached old versions from the CDN for the duration of the cache TTL.

Use one of these strategies:

Strategy 1: Content-addressed filenames (best for JS/CSS)

// In your build tool (webpack/vite), enable content hashing
// Output: main.a3f8d2b1.js — filename changes when content changes
// Cache-Control: public, max-age=31536000, immutable

Strategy 2: API-based purge after deploy (Cloudflare)

curl -X POST "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/purge_cache" \
     -H "Authorization: Bearer $CF_API_TOKEN" \
     -H "Content-Type: application/json" \
     --data '{"purge_everything":true}'

Strategy 3: Cache-Control headers for HTML

location ~* \.html$ {
    add_header Cache-Control "no-cache, must-revalidate";
}
location ~* \.(js|css|png|jpg|woff2)$ {
    add_header Cache-Control "public, max-age=31536000, immutable";
}

HTML files should never be cached aggressively since they reference JS/CSS by filename. Fingerprinted assets can be cached forever because a new deploy generates a new filename.