CDN tuning for application performance

Why this matters

CDN tuning for application performance means setting rules at the edge so users get fast responses with fewer origin trips. A CDN is a content delivery network that stores copies of content closer to users. A clear cache key, modern compression, and a sensible image policy shrink wait time and bandwidth. You can apply these quickly to help reduce wait time.

The technique

I use one simple edge policy for many apps. I keep the cache key clean, compress text, and serve optimized images. Here is how I set it up.

Set a clean cache key

A cache key is the set of request parts the CDN uses to decide when two requests should share the same stored response.

• Base the key on scheme, host, and path only. Add query parameters only when they change content, such as id or page.
• Strip tracking parameters like utm tags and ad click ids before the key is built.
• Normalize the request. Lowercase the host, collapse multiple slashes, and standardize a trailing slash rule.
• Exclude headers and cookies from the key unless content truly varies by them. For authenticated pages, bypass cache or vary on a single session cookie.
• Set practical time to live values for static and dynamic routes. Use stale-while-revalidate so users get a cached response while the CDN checks freshness.

Enable modern compression

Compression reduces the bytes sent for text files without changing what the user sees.

• Turn on Brotli for text types such as HTML, CSS, JavaScript, JSON, SVG, and XML. Fall back to gzip for older browsers.
• Do not include the Accept-Encoding header in the key. Let the CDN choose compression per client.

Enforce a smart image policy

• Auto convert images to WebP or AVIF when the browser supports them. Keep JPEG or PNG when it does not.
• Resize oversized images at the edge. Set max width for common layouts, such as 1920 for banners and 1024 for content images.
• Cache optimized variants by path and size so repeat views reuse the stored file.

Quick checks

• Load a key page and confirm cache status and compression in your browser dev tools network panel.
• Reload the same page with tracking tags added to the URL. The response should still be a cache hit.
• Test an authenticated page to confirm private data is never cached.

How I can help

If you want this tuned for your stack, I can configure and maintain it under Custom Development Features & Add-ons or Engineering Retainers.