Interview frequency: …
Short answer
It is a custom development build containing all of your project's Native libraries and configuration, with advanced debugging tools, avoiding Expo Go's restriction to a predefined set of libraries.
Explanation
Expo Go is great for beginners, but it cannot run libraries that require custom native code or external configuration, such as specialized Bluetooth or advanced video players. Expo Dev Client lets developers create their own development build, combining full native-code flexibility with fast development and Fast Refresh.
Code example
// eas.json
// {
// "build": {
// "development": { "developmentClient": true, "distribution": "internal" }
// }
// }
// Install the dev client, build it once, then iterate with fast refresh:
// npx expo install expo-dev-client
// eas build --profile development --platform ios
// npx expo start --dev-client
// app.config.ts — native libraries added later are included in the next dev build, unlike Expo Go
export default { plugins: ["expo-dev-client", "react-native-vision-camera"] };Common mistakes
- Trying to import libraries that require C++ code or advanced permissions into the regular Expo Go app.
Follow-up questions
- What are Expo Config Plugins, and how do they safely modify native code and libraries?
- How do you diagnose and analyze crash reports with Sentry in Expo apps?