Drupal 11.3 includes a number of significant performance improvements, altogether making it the most significant step forward for Drupal performance in the last 10 years (since the Drupal 8.0.0 release).
These improvements have been driven by enhancements to Drupal's render and caching layers in 11.2.x, notably taking advantage of Fibers, a new PHP feature added in PHP 8.1. By rendering more parts of the page in placeholders, we have enabled similar database and cache operations that used to occur individually to be combined, with particular improvements in path alias and entity loading. We have also learned from Drupal's automated performance testing framework, allowing us to identify and execute several optimizations during Drupal's hook and field discovery processes, to significantly reduce database and cache i/o, and memory usage on cold caches.
On the front end we have converted Drupal's BigPipe implementation to use HTMX, reducing JavaScript weight significantly. We also intercept placeholders with warm render caches prior to BigPipe replacement, so that BigPipe's JavaScript is not loaded at all on requests that will be served quickly without it, allowing BigPipe to be used more widely for the requests that do need it. These changes may also allow us to enable BigPipe for anonymous site visitors in a future release.
