# Flutter Application Architecture (Flutter) > Clean Architecture, layered architecture, modularization, feature-based structure, scalability - 22 interview questions - Senior - [Interview Questions: Flutter](https://sharpskill.dev/en/technologies/flutter/interview-questions.md) ## 1. What are the three main layers of Clean Architecture in a Flutter application? **Answer** Clean Architecture divides the application into three distinct layers: Domain (entities and use cases), Data (repositories and data sources), and Presentation (UI and state management). This separation ensures that business logic remains independent of implementation details like UI frameworks or databases. The Domain layer has no dependencies on other layers, which facilitates testing and maintainability. ## 2. What is the main role of the Domain layer in Clean Architecture? **Answer** The Domain layer contains the pure business logic of the application, including entities (business objects) and use cases. This layer is completely independent of frameworks, databases, and UI. It defines business rules and contracts (interfaces) that other layers must implement, ensuring that the core of the application remains stable despite technical changes. ## 3. Why is the Repository pattern essential in a well-structured Flutter architecture? **Answer** The Repository pattern acts as an abstraction between business logic and data sources. It allows the Domain layer to access data without knowing its origin (API, local cache, database). This abstraction facilitates changing data sources, unit testing with mocks, and managing complex caching strategies while keeping business code clean. ## 19 more questions available - What is the difference between an Entity and a Model in Flutter Clean Architecture? - What is a Use Case (or Interactor) in Clean Architecture? Sign up for free: https://sharpskill.dev/en/login ## Other Flutter interview topics - [Dart Basics](https://sharpskill.dev/en/technologies/flutter/interview-questions/dart-basics.md): 25 questions, Junior - [Dart Language Essentials](https://sharpskill.dev/en/technologies/flutter/interview-questions/dart-language-essentials.md): 15 questions, Junior - [Flutter Fundamentals](https://sharpskill.dev/en/technologies/flutter/interview-questions/flutter-fundamentals.md): 18 questions, Junior - [Widget Lifecycle](https://sharpskill.dev/en/technologies/flutter/interview-questions/widget-lifecycle.md): 20 questions, Junior - [Local Storage](https://sharpskill.dev/en/technologies/flutter/interview-questions/local-storage.md): 20 questions, Junior - [Application Lifecycle](https://sharpskill.dev/en/technologies/flutter/interview-questions/app-lifecycle.md): 20 questions, Junior - [Layouts & Constraints](https://sharpskill.dev/en/technologies/flutter/interview-questions/layouts-constraints.md): 24 questions, Mid-Level - [ListView & GridView](https://sharpskill.dev/en/technologies/flutter/interview-questions/listview-gridview.md): 25 questions, Mid-Level - [Navigation & Routing](https://sharpskill.dev/en/technologies/flutter/interview-questions/navigation-routing.md): 22 questions, Mid-Level - [Basic State Management](https://sharpskill.dev/en/technologies/flutter/interview-questions/state-management-basics.md): 22 questions, Mid-Level - [Provider Pattern](https://sharpskill.dev/en/technologies/flutter/interview-questions/provider-pattern.md): 18 questions, Mid-Level - [Networking & HTTP](https://sharpskill.dev/en/technologies/flutter/interview-questions/networking-http.md): 20 questions, Mid-Level - [JSON Serialization](https://sharpskill.dev/en/technologies/flutter/interview-questions/json-serialization.md): 20 questions, Mid-Level - [Local Database](https://sharpskill.dev/en/technologies/flutter/interview-questions/local-database.md): 22 questions, Mid-Level - [Forms & Validation](https://sharpskill.dev/en/technologies/flutter/interview-questions/forms-validation.md): 20 questions, Mid-Level - [Animations](https://sharpskill.dev/en/technologies/flutter/interview-questions/animations.md): 20 questions, Mid-Level - [Firebase Integration](https://sharpskill.dev/en/technologies/flutter/interview-questions/firebase-integration.md): 18 questions, Mid-Level - [Unit Testing](https://sharpskill.dev/en/technologies/flutter/interview-questions/unit-testing.md): 20 questions, Mid-Level - [Widget Testing](https://sharpskill.dev/en/technologies/flutter/interview-questions/widget-testing.md): 18 questions, Mid-Level - [Build & Deployment](https://sharpskill.dev/en/technologies/flutter/interview-questions/build-deployment.md): 16 questions, Mid-Level - [Package Management](https://sharpskill.dev/en/technologies/flutter/interview-questions/package-management.md): 16 questions, Mid-Level - [Memory & Performance](https://sharpskill.dev/en/technologies/flutter/interview-questions/memory-performance.md): 22 questions, Senior - [Streams & RxDart](https://sharpskill.dev/en/technologies/flutter/interview-questions/streams-rxdart.md): 24 questions, Senior - [Advanced State Management](https://sharpskill.dev/en/technologies/flutter/interview-questions/advanced-state-management.md): 26 questions, Senior - [Flutter Design Patterns](https://sharpskill.dev/en/technologies/flutter/interview-questions/flutter-design-patterns.md): 24 questions, Senior - [Performance Optimization](https://sharpskill.dev/en/technologies/flutter/interview-questions/performance-optimization.md): 26 questions, Senior - [Platform Channels](https://sharpskill.dev/en/technologies/flutter/interview-questions/platform-channels.md): 20 questions, Senior - [Custom Painting](https://sharpskill.dev/en/technologies/flutter/interview-questions/custom-painting.md): 22 questions, Senior --- Source: SharpSkill (https://sharpskill.dev), tech interview preparation for your real stack. 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