# Offline-First Architecture (React Native) > NetInfo, sync strategies, conflict resolution, queue management, offline UX - 20 interview questions - Senior - [Interview Questions: React Native](https://sharpskill.dev/en/technologies/react-native/interview-questions.md) ## 1. What is offline-first architecture in the context of a mobile application? **Answer** Offline-first architecture is a design approach where the application is built to work primarily with local data, with server synchronization being secondary. Data is stored locally first and synced with the backend when connectivity is available. This approach ensures a smooth user experience even without network connection, unlike the online-first approach that depends on connectivity to function. ## 2. Which package should be used to detect network connection state in React Native? **Answer** @react-native-community/netinfo is the standard package for detecting network connection state in React Native. It provides information about whether the device is connected, the connection type (WiFi, cellular), and offers listeners to react to connectivity changes in real-time. It's an essential component for implementing offline-first architecture. ## 3. How to use NetInfo to listen for connectivity changes in real-time? **Answer** NetInfo.addEventListener allows subscribing to connectivity changes and returns an unsubscribe function. This function should be called in useEffect cleanup to prevent memory leaks. The callback receives a state object containing isConnected, type, and other information about the current connection. This approach is essential for dynamically reacting to network changes. ## 17 more questions available - What is the difference between isConnected and isInternetReachable in NetInfo? - Which synchronization strategy to use for an offline-first note-taking application? Sign up for free: https://sharpskill.dev/en/login ## Other React Native interview topics - [JavaScript Essentials](https://sharpskill.dev/en/technologies/react-native/interview-questions/javascript-essentials.md): 25 questions, Junior - [React Fundamentals](https://sharpskill.dev/en/technologies/react-native/interview-questions/react-fundamentals.md): 20 questions, Junior - [React Native Basics](https://sharpskill.dev/en/technologies/react-native/interview-questions/react-native-basics.md): 22 questions, Junior - [React Hooks](https://sharpskill.dev/en/technologies/react-native/interview-questions/react-hooks.md): 20 questions, Junior - [TypeScript for React & React Native](https://sharpskill.dev/en/technologies/react-native/interview-questions/typescript-for-react-native.md): 22 questions, Junior - [React Native Components & API](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-components-api.md): 20 questions, Junior - [React Native Styling & Layout](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-styling-layout.md): 18 questions, Junior - [React Native Navigation](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-navigation.md): 22 questions, Mid-Level - [React Native State Management](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-state-management.md): 24 questions, Mid-Level - [React Native Networking & API](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-networking-api.md): 20 questions, Mid-Level - [Data Persistence](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-data-persistence.md): 20 questions, Mid-Level - [Forms & Validation](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-forms-validation.md): 18 questions, Mid-Level - [React Native Animations](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-animations.md): 22 questions, Mid-Level - [Native Modules & Bridge](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-native-modules.md): 20 questions, Mid-Level - [Platform-Specific Code](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-platform-specific-code.md): 18 questions, Mid-Level - [Permissions & Device APIs](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-permissions-apis.md): 20 questions, Mid-Level - [Push Notifications](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-push-notifications.md): 18 questions, Mid-Level - [React Native Testing](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-testing.md): 20 questions, Mid-Level - [React Native Debugging](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-debugging.md): 18 questions, Mid-Level - [Build & Deployment](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-build-deployment.md): 20 questions, Mid-Level - [Expo vs React Native Bare](https://sharpskill.dev/en/technologies/react-native/interview-questions/expo-vs-bare-rn.md): 18 questions, Mid-Level - [Performance Optimization](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-performance-optimization.md): 24 questions, Senior - [Memory Management](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-memory-management.md): 20 questions, Senior - [Architecture Patterns](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-architecture-patterns.md): 22 questions, Senior - [React Native New Architecture](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-new-architecture.md): 24 questions, Senior - [Security Best Practices](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-security-best-practices.md): 20 questions, Senior - [React Native CI/CD](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-ci-cd.md): 20 questions, Senior - [Monorepo & Code Sharing](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-monorepo-architecture.md): 18 questions, Senior - [Advanced Topics](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-advanced-topics.md): 22 questions, Senior - [App Lifecycle & Background Execution](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-app-lifecycle-background.md): 20 questions, Mid-Level - [Authentication & Session Management](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-auth-session-management.md): 22 questions, Mid-Level - [Monitoring & Crash Reporting](https://sharpskill.dev/en/technologies/react-native/interview-questions/rn-monitoring-crash-reporting.md): 20 questions, Senior --- Source: SharpSkill (https://sharpskill.dev), tech interview preparation for your real stack. 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