Building Native UI with React Native and Expo

Overview

React Native UI differs fundamentally from web UI. There is no CSS, no DOM, no browser layout engine. Everything renders to native platform views through a bridge. Understanding this architecture prevents the most common mistakes.

Core principle: Think in native components and Flexbox, not in HTML/CSS. Every visual element maps to a platform-native view.

When to Use

• Building screens, components, or layouts in React Native
• Implementing navigation between screens
• Adding animations or gesture interactions
• Using native platform controls (switches, sliders, segmented controls)
• Styling components (StyleSheet, not CSS)
• Creating modals, form sheets, or bottom sheets

Navigation with Expo Router