Learning Kotlin Multiplatform

Introduction

The book "Exploring Kotlin Multiplatform" (2022) by Salman Mirza is arguably one of the most comprehensive and practical guides to the Kotlin Multiplatform (KMP) technology. In a world where business demands rapid deployment across multiple platforms, KMP offers an elegant way to share business logic between Android, iOS, web, and desktop while maintaining native UI performance. The author, an experienced developer and consultant, does not simply paraphrase the documentation — he guides the reader through real-world scenarios, from environment setup to application publication.

What This Book Is About

The 410-page book covers the full lifecycle of a cross-platform project. It starts with the basics: what KMP is, how it differs from Flutter or React Native, and why you should choose it. The author then delves into architecture: modules, expect/actual mechanisms, serialization, networking, and databases. Special attention is given to integration with native platforms — you will learn how to call Swift/Objective-C code from Kotlin and vice versa. The second half of the book is dedicated to advanced topics: testing shared code, CI/CD, creating libraries, and publishing to Maven.

Who This Book Is For

The book is aimed at developers already familiar with Kotlin (or Java) and having a basic understanding of mobile development. If you are an Android developer looking to expand your skills to iOS, or an iOS developer wanting to learn Kotlin, this is an excellent starting point. The book will also be useful for team leads and architects evaluating KMP for their projects.

What the Reader Will Learn

• KMP Basics: how shared modules, expect/actual, and Gradle configuration work.
• Architecture: Clean Architecture with KMP, MVVM, dependency injection (Koin, Kodein).
• Networking and Data: Ktor, SQLDelight, multithreading with kotlinx.coroutines.
• Platform Integration: calling native UI (Compose Multiplatform, SwiftUI), working with camera, geolocation.
• Testing: unit tests for shared code, multiplatform tests.
• CI/CD: setting up GitHub Actions, Fastlane, publishing to App Store and Google Play.
• Creating Libraries: how to write and publish your own KMP library.

Strengths

The first thing that stands out is the practical focus. Each chapter contains ready-to-run code examples. The author is not afraid to show the "messy" details: how to deal with circular dependencies, how to optimize the build for iOS, how to debug shared code in Xcode. The second is relevance. The book was published in 2022, when KMP had already become stable, and it describes library versions that are still relevant (Ktor 2.x, SQLDelight 1.5, Compose Multiplatform 1.0). The third is structure. The material is divided into logical blocks, from simple to complex, with summaries and self-assessment questions at the end of each chapter.

Who It Is Recommended For

I recommend this book to anyone who wants to learn Kotlin Multiplatform from scratch or systematize existing knowledge. It will be useful both for individual developers and for teams transitioning to cross-platform development. The only caveat: if you are not familiar with Kotlin at all, first read an introduction to the language — the book assumes confident knowledge of syntax and basic concepts.

Overall, "Exploring Kotlin Multiplatform" is a high-quality, in-depth, and practical resource that should be on the shelf of every developer interested in KMP. On the PythonLib website, we give it a rating of 9/10 for completeness and relevance.