How to Catch Magento 2 Performance Regressions Automatically in CI Pipelines

Performance regressions in Magento 2 can silently slip through after routine code changes, such as a minor tax observer update that spikes Time to First Byte by hundreds of milliseconds. The recommended approach involves defining hard performance budgets — written thresholds for metrics like TTFB, LCP, and query times — stored directly in the project repository. Lighthouse CI can then be wired into the CI pipeline to run automated headless browser checks against a stable, cache-warmed staging environment and block pull requests that breach those budgets. Beyond frontend metrics, backend regressions caused by injected plugins or N+1 queries require additional HTTP-level and load-testing layers to surface problems that browser tools would never detect. The core principle is that performance must be treated as an ongoing, protected property of the codebase, with automated gates that catch slowdowns before deployment rather than after.