Containerized Stack

HTTP Caching at the Edge

Full-page and block-level HTTP caching with ESI support, Magento-aware cache rules, and config reloads that keep the cache warm.

Full-Page and Block-Level HTTP Cache

Varnish sits between OpenResty and the PHP backend as an HTTP reverse proxy cache. When a cacheable page is requested, Varnish serves it directly from memory without touching PHP or the database. For Magento storefronts, this means category pages, product pages, and CMS blocks are served in single-digit milliseconds after the first request warms the cache.

ESI for Partial Page Caching

Edge Side Includes (ESI) allow Varnish to cache a page in fragments. A product page can have its main content cached for hours while the cart block and user-specific sections are fetched fresh on each request. Magento's built-in ESI support tags these blocks automatically — Varnish assembles the final response from cached and uncached fragments in a single pass.

Config Changes Without a Cold Cache

When the cache rules change, the new VCL is compiled, checked, and switched in on the running Varnish, with no restart. The cache stays warm through the change, so shoppers never get a slow wave of uncached pages after an update. A VCL that fails to compile is rejected before it goes live.

Magento-Aware Cache Rules

The VCL is generated from the store's own Magento installation and then tuned by the platform: static assets are cached without cookies, every PHP container is allowed to purge, and cache headers that reveal internal details are stripped from responses. Stores that need their own rules can supply a custom VCL, which the platform keeps in place. Memory for the cache is sized per environment to fit the catalog and traffic. Read the Varnish docs for VCL, ESI, and cache invalidation details.