The PHP Deprecations That Break Old WordPress Code
Dynamic properties are deprecated as of PHP 8.2.0, and WordPress.com said in 2024 that behavior deprecated in that release will be removed in PHP 9.
Engineering
Engineering
PHP, HTTP, databases and the measurements that tell you which of them is actually slow.
EngineeringTurning On Slow Query Logging Without Filling the Disk
MySQL 8.4 allows database administrators to enable, disable, and retarget the slow query log entirely at runtime.
REST API or admin-ajax: Choosing the Right Endpoint
Omitting a permission_callback from register_rest_route has broken custom endpoint registrations since WordPress 5.5.0 treats missing authorization checks as an error.
Engineering currently holds 9 pages. They are dated 2007 to 2026. Nothing is filed here because it was popular. A page joins this section when it answers a question that came up while something was actually being built.
Every version, date and default quoted in this section is carried over from published documentation. None of it is estimated, and none of it is refreshed to look current. There are no scores here, no top-ten lists and no affiliate recommendations; anything published for a third party sits under Partner content and says so.
Order here is chronological, most recent first. A page does not move up because it is being read more; it moves only when something newer is published. That makes the foot of the list the oldest material on the subject, which is worth knowing before you follow a setting or a command from it into a current install. The most recent of them is Turning On Slow Query Logging Without Filling the Disk, published 2026-09-29.
Everything in Engineering
Front page- Engineering
Measuring Core Web Vitals on a Real Site, Not in a Lab
A clean Lighthouse run can mislead an engineering team for months. Synthetic audits run in a controlled environment with predefined device and network settings, generating a single score under static conditions.
- Engineering
Indexes for Content Sites, Without the Theory
A database index fails to accelerate a query when the structure of the index does not match how the execution engine reads data.
- Engineering
Cache-Control for a Content Site, Explained by What Breaks
IETF RFC 9111, published on June 6, 2022, established the baseline rules that govern modern web caching
- Engineering
Saving Post Meta Field Revisions in WordPress
If your plugin or theme uses custom post meta fields then you may want to store revisions to these fields when a post revision is saved.
- Engineering
Basic Authentication with the WordPress HTTP API
Basic Authentication (or BasicAuth) is not natively handled with the WordPress HTTP API.
- Engineering
Questionably Useful Thing: Really Big Source Text
Update (11th August 2007): We now have numbers! View-source. You’ve gotta love it. But it’s a bit boring sometimes – line after line of hypertext, with the only highlight being nice indentation if you’re lucky.