ll walk through a practical, layered approach to Magento 2 performance regression testing that works whether you t block anything. Abudgetis a hard, written threshold that a pull request must respect: );if(microtime(true)-$start>$threshold){thrownew\RuntimeException( Redis is warm, Varnish is humming, your slow SQL is gone, and the storefront scores in the green. Then a two-line change to a tax observer ships on a Friday, and on Monday your TTFB is up 400ms and the checkout queue is backing up.