How to scale an AEM site expected to have millions of users where AEM social communities is not in use?

Steps

For scalability, there are many ways to optimize the site.  Here are a few ways:

1. Use Adobe Target or AEM personalization for personalized content so most of the page can be cached.
2. Use Sling Dynamic Includes to do ESI calls for caching the user's personalized info. This helps avoid numerous back end calls while still caching the rest of the AEM page.
3. Apply Cache-Control header for caching in CDN and browser.
4. To benefit from performance enhancements to Oak repository and its User Management, implement the site on the latest AEM version.