Caching Strategies for Dynamic Sites
Caching static brochure pages is straightforward, but sites with logged-in users, shopping baskets or personalised content need a more careful strategy. The challenge is serving cached pages where it is safe while always showing each visitor their correct, up-to-date information.
Get it right and a dynamic site can feel almost as fast as a static one.
The Tricky Balance
Dynamic sites are harder to cache because parts of each page are personal while much of it is shared. The skill lies in caching the shared, heavy elements aggressively while keeping the personal details fresh, so visitors get speed without ever seeing the wrong information.
The Goal We Aim For
The target for a dynamic site is to feel almost as quick as a static one without ever showing the wrong information. That balance is achievable with a careful, layered caching strategy.
- Cache everything that is safe to share.
- Keep personal content accurate and current.
- Serve repeat visits quickly.
- Update cached content promptly when it changes.
Keeping Cached Pages Correct
The hardest part of caching dynamic sites is making sure people always see accurate information. A cache that serves the wrong basket or an out-of-date price is worse than no cache at all, so the rules need care.
- Define exactly which pages and fragments are safe to cache.
- Vary the cache by the factors that change the output.
- Clear the right entries automatically when data changes.
- Test logged-in and logged-out journeys thoroughly.
Layers of Caching
- Page cache: whole pages stored for anonymous visitors.
- Object cache: reusable pieces such as query results.
- Fragment cache: caching the stable parts of an otherwise personalised page.
Handling Personalised Content
- Serve cached pages to logged-out visitors who all see the same thing.
- Bypass the cache for personalised areas like baskets and accounts.
- Cache the heavy, shared building blocks even on dynamic pages.
- Clear the right cache automatically when content changes.
If you need a hand with any of this, your Progressive Robot delivery team is ready to help. Raise a ticket from the Support area of your client portal or speak to your account manager and we will guide you through the next steps.