React Native's New Architecture in Production: What JSI, Fabric, and TurboModules Actually Change

React Native's New Architecture — JSI, Fabric, and TurboModules — has been "coming soon" for long enough that some teams wrote it off as vaporware. It shipped. It is now default in new React Native projects. And it meaningfully changes how the framework works at the performance-critical boundaries between JavaScript and native code. This post is not a getting-started guide. It is an honest account of what the New Architecture actually changes in production applications — which performance improv