Kraken, a leading cryptocurrency platform, has detailed its journey to adopt the New Architecture for React Native, which will become the default starting from React Native 0.76 and Expo SDK 52. The New Architecture promises improved performance, and Kraken, which has three mobile apps written in React Native, saw significant improvements in areas such as complete app renderer (1.3x faster), home screen renderer (2.5x faster), and trading flow screen render (5.3x faster).
Kraken’s plan involved updating third-party component libraries and migrating internal components to support both the new and old renderer, updating third-party native module libraries and migrating internal libraries to Native Turbo Modules, enabling bridgeless mode, and removing backwards compatibility once fully rolled out.
The company faced a few speed bumps during the adoption, such as Swift support for Fabric components, automatic batching issues, and bridgeless mode. However, these were resolved through interop layers, refactoring, and adopting the New Architecture last due to its comparatively lesser disruptive nature.
Overall, the New Architecture adoption led to stability on par with the old architecture and improved performance, with the biggest improvements seen on slower devices. However, the native cold start got slightly slower due to increased app binary size. Looking ahead, Kraken plans to further leverage the new capabilities gained, such as using useDeferredValue for frequently updated components, fixing instances of jumpy layouts, and exposing existing Rust libraries from the backend to the apps via JSI bindings.
