List every app, pixel, tag manager rule, chat tool, review widget, and consent script. Add an owner and business purpose so dead code is easy to spot.
Duplicate the live theme. Change one thing, use the same page and device, and record what happened. If the change breaks a customer path, roll it back before touching production.
Check the home, collection, product, cart, and checkout path on a phone. Confirm the page still works with a slow connection and that the business owner for the feature agrees it can change.
List every app, pixel, tag manager rule, chat tool, review widget, and consent script. Add an owner and business purpose so dead code is easy to spot.
Source: Shopify theme performance guidance. Reviewed Sep 22, 2026.