WooCommerce

Currently, WooCommerce blocks rely on server-side hydration to inject cart data directly into the initial HTML response, which requires waiting for the server to process and render dynamic cart information before the page can be delivered to users. This server-side processing adds 200-800ms (or 2-3+ seconds on slower hosting) to every page load, directly impacting FCP, LCP and improves perceived UX performance. By contrast, CDN-cached pages can be delivered to users in under 50ms from edge locations, but currently cannot be used for cart, checkout, or product pages because they require this dynamic data at render time.

This feature toggled on, would enable support for full CDN caching of WooCommerce store pages by replacing server-side hydration with instant skeleton rendering and asynchronous data fetching. Pages would load immediately from the CDN with visual skeleton states, while cart quantity data is populated from localStorage (providing instant feedback in 1-2ms) and validated through background API requests. This architectural shift dramatically improves perceived performance, instead of waiting 500ms+ for a server to hydrate and deliver a complete page, users see usable content instantly and cart information appears within milliseconds from locally cached data. The mini-cart icon, for example, would display the correct item count immediately from localStorage rather than waiting for a server round-trip. This approach leverages the performance benefits of CDN edge caching (10-20x faster than origin requests) while maintaining data accuracy through background API validation, resulting in measurably faster FCP, LCP, and significantly improved user experience, especially for mobile users on slower connections.

The implementation involves synchronizing cart state between the IAPI store and Redux’s existing localStorage persistence layer, updating frontend components to prioritize cached data on initial render while always validating with the API in the background, and introducing server-side filters to disable hydration when CDN mode is enabled. This can be rolled out as an experimental feature flag to allow thorough testing before becoming a standard optimization for stores using CDN providers like Cloudflare, Fastly, or AWS CloudFront.

There was a draft PR, which works for cart page, more work to ensure it works for checkout and now with IAPI, there needs to be some front-end update to ensure its compatible.
https://github.com/woocommerce/woocommerce/pull/55693