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

What this post added

This post details Shopify's successful migration of its large mobile applications (Shopify Mobile and Shopify POS) to React Native's New Architecture. It outlines the guiding principles of minimizing code changes, maintaining dual architecture compatibility, and ensuring performance parity. The migration strategy involved dual architecture testing via TopHat, conditional functionality using feature flags, and updating dependencies. Key technical challenges and their solutions are discussed, including state batching, blank screen issues, shadow tree manipulation, view flattening, and legacy native module main thread usage. Animation performance concerns with Reanimated were also addressed. The post details a gradual rollout approach for both Android and iOS, along with an emergency response plan. The team deferred full TurboModule migration to focus on initial compatibility, making minimal app code changes and leveraging latest React Native versions.