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React Native JSI Deep Dive — Part 1: React Native Architecture — Threads, Hermes, and the Event Loop - HeartIT
You've built React Native apps for years. You know `useState`, you know `FlatList`, you know how to call a native module. But do you know what happens in the 16 milliseconds between your `onPress` handler and the pixel changing on screen? Three execution threads, two runtime environments (JavaScript via Hermes, native via Objective-C/Java/C++), and a message-passing architecture that explains every performance problem you've ever had.