Modern Android App Architecture

Examine the goals of system design principles to produce clean, readable, and maintainable code with strong testability, separation of concerns, and adherence to dry and solid practices.

Apply the Kiss principle, keep it simple and avoid overengineering, by breaking problems into smaller subproblems and solving them step by step to improve maintainability.

Apply the single responsibility principle to refactor the demo app's nodes manager and nodes persistence. Group load, save, and delete with persistence and keep share separate, improving testability and readability.

Discover model-view-intent (MVI): a single immutable state, one-way flow, and a pure reducer that maps intents to new states, with one-off effects.

Explore the MVI pattern by implementing intents, state, and one-time effects in a nodes module, demonstrating load, add, delete, and share actions with snack bar feedback and unidirectional data flow.

Explore VIPER architecture for Android, detailing the five components—view, interactor, presenter, entity, router—each with a single responsibility, interfaces, and testable boundaries that separate the user interface from logic.

See VIPER applied on Android with view, presenter, interactor, and router separation. Explore two features: add node and nodes list, showing interfaces, lifecycle handling, and testable dependencies.

Explore the goals and strategies of clean architecture as defined by Uncle Bob, examine its components, and discuss when to use it with practical use cases.

Explore the goals of clean architecture—development, deployment, operation, and maintenance—to minimize costs, maximize programmer productivity, and leverage modularization with stable interfaces in mobile apps.

Learn how the UI layer, powered by viewmodels, translates data from the data layer into immutable UI state for rendering, with unidirectional data flow and events via LiveData.

Explore the UI and domain layer changes, including a sealed notes UI state with loading, error, and content, exposed via a state flow, and a new sync use case.

Learn to implement coroutines with Kotlin flows in an Android app using ViewModel and lifecycle scopes, avoid LiveData, and optimize flow collection with hot state flows and lifecycle-aware collection.

Explore the service locator pattern as an alternative to dependency injection, where a central locator creates and exposes dependencies to classes on demand, highlighting its decoupling, testing, and scoping trade-offs.

Examine component cohesion and coupling to design maintainable multi-module Android apps. Compare modularization strategies: separation by layer, by feature, and by layer-feature, across multimodal app models with a notes demo.

Apply modularization to the notes app by separating data, domain, and UI layers, adopt Gradle version catalogs, and enable dependency injection with Hilt for decoupled, testable architecture.