Can you list the main architectural levels used in Flutter applications?

In Flutter applications, several architectural layers are usually distinguished:

• Presentation Layer — responsible for displaying the UI and user interaction. Flutter widgets are used here.

• Business Logic Layer — contains the application logic, event handling, and state. Often implemented using state management patterns (e.g., BLoC, Provider, Riverpod).

• Data Layer — responsible for data retrieval and storage, interacting with APIs, databases, or local storage.

This separation helps keep the code clean, modular, and testable.