Engineering2 min read

The AEM Performance Audit Checklist (Before You Blame the CDN)

akenside.ai team·

Most AEM slowness is self-inflicted

When an AEM site feels slow, the CDN gets blamed first, but the real culprits are usually upstream: uncached dispatcher responses, heavy client libraries, and components doing too much work per request. Here's the checklist we run before recommending a single infrastructure change.

1. Dispatcher & caching

  • Are HTML responses being cached, or is something (a cookie, a query param, a Cache-Control header) busting the cache on every hit?
  • Is the dispatcher cache invalidation surgical, or does every publish flush everything?
  • Are static assets fingerprinted and far-future cached?

2. Client-side weight

  • Total client-library payload, how much JS/CSS ships on first load, and how much is used?
  • Are libraries concatenated and minified, or shipping as dozens of requests?
  • Lazy-load below-the-fold components and images.

3. Server-side rendering cost

  • Which components are expensive to render? (Sling Models doing synchronous service calls, deep resource resolution, uncached queries.)
  • Are JCR queries indexed, or are they traversing?

4. Core Web Vitals that matter

  • LCP, usually a hero image or web font. Preload the LCP image; subset and preload fonts.
  • CLS, reserve space for images/embeds; avoid late-injected banners.
  • INP, keep main-thread work small; defer non-critical JS.

5. The measurement loop

Fix nothing until you can measure it. Capture real-user metrics (field data), not just lab scores, and re-measure after each change so you know what helped.

Want this done for you?

Our AEM Health & QA Audit runs this checklist against your site and returns a prioritised remediation backlog, performance, dispatcher config, accessibility and content-model smells, so your team fixes the highest-impact issues first.

See the AEM audit →