Caching

WooCommerce product recommendations with your own scoring WooCommerce upsells and cross-sells are curated by hand: the shop owner links related products one by one. On a store with hundreds of products nobody keeps that up to date. A simple algorithm based on what customers actually bought together, weighted by category, gives a relevant “Customers also…

WordPress HTTP API: wp_remote_get() and wp_remote_post() best practices The WordPress HTTP API (wp_remote_get(), wp_remote_post(), wp_remote_request()) wraps the transport (cURL or PHP streams) in one interface with the same arguments and the same response format everywhere. Used carelessly it gives silent failures, hung pages and API rate limits; used well it needs four habits: check errors,…

Cache expensive operations with the WordPress Transients API The Transients API stores cached data with an expiration time. The same set_transient() and get_transient() calls use the wp_options table on a default install and memory (Redis, Memcached) when a persistent object cache is active, without any code changes. Good candidates are remote API responses, heavy WP_Query…

Offline support for a WordPress site with a service worker and Workbox A service worker is a script that the browser runs between the page and the network. It can answer requests from a cache, so pages the visitor has seen, or pages the site marks as important, open without a connection. For an event…

Lower WordPress TTFB with Redis as a persistent object cache WordPress caches options, posts, terms and user data in memory, but only for one request. The next request asks MySQL again. A persistent object cache keeps these values in Redis between requests, so a page that needed 80 queries needs 10. It helps where a…

Stale-while-revalidate caching with WordPress transients A normal transient has one weak moment: when it expires, the next visitor waits while the expensive value is rebuilt, and on a busy site several visitors rebuild it at the same time. Stale-while-revalidate avoids both: after the “fresh” time the old value is still served, and a single background…

Faster WooCommerce product archives: lookup tables and cached queries A shop category with a few thousand products, price sorting and attribute filters can take seconds to render. WooCommerce has its own tables to make these queries cheaper, the product meta lookup table and the attributes lookup table, but they help only when they are filled…

Set up Nginx FastCGI page caching for WordPress so anonymous page views are served directly from disk without hitting PHP-FPM or MySQL, dramatically reducing server load.

Cookies in WordPress: set, read and delete them safely A dismissed banner, a list or grid view, the last visited category: small preferences like these are often stored in a cookie. PHP’s setcookie() does the job, but in WordPress there are details to get right: when to call it, which path and domain to use,…