Clean Architecture layers in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of the Presentation Layer in Clean Architecture?

The Presentation Layer handles the user interface and user interaction. It displays data and sends user actions to the next layer without knowing business logic details.

beginner

Which layer contains the business rules and application logic in Clean Architecture?

The Domain Layer contains business rules and application logic. It is independent of UI and data sources, focusing on what the app does.

beginner

What role does the Data Layer play in Clean Architecture?

The Data Layer manages data sources like databases, network, or cache. It provides data to the Domain Layer and hides details of data fetching or storage.

intermediate

Why is it important that the Domain Layer is independent of other layers?

Independence allows the Domain Layer to be reusable and testable. Changes in UI or data sources don’t affect business rules, making the app easier to maintain.

intermediate

How do layers communicate in Clean Architecture?

Layers communicate through interfaces or abstractions. Higher layers depend on lower layers’ interfaces, not their implementations, ensuring loose coupling.

Which layer in Clean Architecture is responsible for fetching data from a remote server?

A Presentation Layer

B Domain Layer

C Data Layer

D UI Layer

The Data Layer handles data fetching from sources like remote servers or databases.

What does the Domain Layer mainly contain?

A Business rules and logic

B User interface code

C Network calls

D Database schemas

The Domain Layer contains the core business rules and application logic.

Why should the Domain Layer be independent of the Data Layer?

A To allow UI changes without affecting business logic

B To make the app slower

C To mix UI and data code

D To avoid testing

Independence allows business logic to remain stable even if data sources or UI change.

Which layer directly interacts with the user in Clean Architecture?

A Data Layer

B Domain Layer

C Repository Layer

D Presentation Layer

The Presentation Layer handles user interaction and displays information.

How do layers in Clean Architecture communicate?

A Directly accessing each other's code

B Through interfaces or abstractions

C By sharing variables globally

D Using UI events only

Using interfaces keeps layers loosely coupled and easier to maintain.

Explain the responsibilities of each layer in Clean Architecture and why this separation helps in app development.

Think about who talks to the user, who holds the app’s rules, and who manages data.

Describe how communication between layers happens in Clean Architecture and why it is designed that way.

Imagine layers as friends who only talk through letters, not by visiting each other’s homes.