Migrating to React Native's New Architecture (2025) - Shopify

This post details the successful migration of Shopify Mobile and Shopify Point of Sale (POS) to React Native's New Architecture. It outlines the migration strategy, focusing on minimizing code changes, maintaining dual architecture compatibility, and ensuring performance and stability parity. The post details the technical process, including native module strategy (not migrating to TurboModules initially, using feature flags), dependency management, upgrading to the latest React Native version, and minimal app code changes. It also highlights common migration issues such as state batching exposing component issues, the 'blank screen of doom' often related to TurboModules, shadow tree manipulation changes impacting UI, view flattening side effects with refs, and legacy native modules blocking the main thread on iOS. Performance concerns with Reanimated are discussed, along with the collaborative effort to address them. Finally, a detailed rollout strategy for Android and iOS is presented, along with an emergency response plan.