Kotlin Application Architecture: From Basics to Production

The book "Kotlin Application Architecture" is a practical guide for developers striving to create scalable, testable, and maintainable projects in the Kotlin language. Unlike many tutorials that focus on syntax, this book is dedicated specifically to architectural decisions: from choosing patterns to organizing code in large teams.

What is this book about?

The author systematically examines real-world development scenarios. You will start with the basics: why traditional approaches (e.g., MVC) work poorly in Kotlin, and what alternatives the ecosystem offers. Then you will move on to advanced topics:

• Clean Architecture — how to split an application into layers (domain, data, presentation) without getting tangled in dependencies.
• Multi-module architecture — when and how to split a project into Gradle modules to speed up builds and simplify teamwork.
• Dependency Injection (DI) — a detailed breakdown of Dagger 2, Hilt, and Koin with code examples.
• Asynchrony — coroutines and Flow: building reactive chains, error handling, and testing.
• Architecture testing — how to write unit tests for UseCase, Repository, and ViewModel without being tied to frameworks.

Who is this book for?

The book is intended for developers already familiar with basic Kotlin syntax (functions, classes, lambdas) and with experience creating at least one small application. You will learn:

• How to stop getting confused by architectural patterns (MVP, MVVM, MVI) and choose the right one for your project.
• How to organize code so that it can be easily modified six months later without the risk of breaking everything.
• How to introduce DI and coroutines into an existing project without a full refactoring.
• How to test complex asynchronous scenarios using kotlinx-coroutines-test.

Why is this book useful?

Each chapter contains not only theory but also ready-made code examples that can be applied immediately. The author shares "pitfalls": for example, why Dagger can slow down builds if modules are organized incorrectly, or how to avoid memory leaks when using coroutines in Android. At the end of the book, there is a full case study: building the architecture of a food ordering application from scratch, from Gradle setup to deployment.

If you are tired of "spaghetti code" and want to write professionally in Kotlin, this book will be your guide in the world of clean architecture.