Practical Kotlin Deep Dive unpacks the "how" and "why" behind Kotlin from core language fundamentals and internal mechanisms to the design of its APIs. It spans Kotlin basics, the standard library, coroutines, kotlinx libraries, compiler internals, and Kotlin Multiplatform.
This book goes beyond surface-level APIs by diving into Kotlin's internals: it walks through real Kotlin function implementations, demystifies generated bytecode, and explains how the Kotlin compiler interprets the language. It also draws directly from KEEP proposals, JetBrains YouTrack discussions, and compiler source code to connect concepts to their origins and design rationale.
Paperback and hardcover editions are being prepared on Amazon
Google Developer Expert for Android and Firebase
Deep dive into Kotlin fundamentals and become a better Kotlin developer
Each topic provides detailed explanations that go beyond surface-level knowledge, exploring not just how Kotlin features work but why they were designed that way. You'll understand the reasoning behind design decisions and trade-offs.
The "Pro Tips for Mastery" sections dive deeper into advanced topics, uncovering internal structures of the Kotlin fundamentals, and offering expert insights that you can apply immediately to write better code.
You'll find references to KEEP (Kotlin Evolution and Enhancement Process) proposals, JetBrains YouTrack discussions, and compiler source code, giving you direct insight into the design decisions behind the language.
From Language Fundamentals to Standard Library, Coroutines, Compiler and Plugins, and Kotlin Multiplatform - this book covers practical knowledge that makes a real difference in how you write, debug, and optimize Kotlin code.
Five comprehensive chapters covering all aspects of Kotlin development
Covers the fundamental building blocks of Kotlin, from null safety and type system design to advanced features like sealed classes, inline functions, and delegation. You'll explore the language's design philosophy by referencing KEEP proposals and discussions from Kotlin language engineers.
Dives into Kotlin's rich standard library, exploring collections, sequences, scope functions, and the utilities that make Kotlin code expressive and concise. Understanding these tools is essential for writing idiomatic Kotlin code.
Provides an extensive exploration of Kotlin's approach to asynchronous programming. From basic concepts like suspending functions and coroutine builders to advanced topics like structured concurrency, Flow, and exception handling.
Explores the official Kotlin libraries developed by JetBrains that extend the language with additional functionality. These libraries provide specialized capabilities for serialization, date/time handling, and immutable collections.
Takes you behind the scenes of how Kotlin code becomes executable programs. You'll learn about the compiler's architecture, the K2 compiler and its improvements, FIR, IR, and how to create compiler plugins.
Explores Kotlin's cross-platform capabilities, covering project structure, source set hierarchies, platform interoperability, and Compose Multiplatform for shared UI development. As multiplatform adoption grows, this knowledge becomes increasingly valuable.
"Since Kotlin was designated as the official language for Android development, it has been loved by many developers. Today, it has grown beyond Android and continues to prove its potential across a wide range of platforms.
In real-world Kotlin development, you inevitably run into all kinds of issues. As you work through them, you naturally start peeking under the hood, and many of us end up wanting to understand Kotlin more deeply.
This book is written for exactly those developers. It takes a deep dive into Kotlin's core principles and internal mechanisms. If you're a Kotlin developer who wants to truly understand the language and expand your technical spectrum to the next level, I highly recommend giving this book a read."
Kotlin은 안드로이드 개발의 공식 언어로 지정되면서 많은 개발자에게 사랑받기 시작했고, 지금은 안드로이드를 넘어 다양한 플랫폼으로 뻗어나가며 그 가능성을 보여주고 있습니다.
실무에서 Kotlin을 사용하다 보면 필연적으로 다양한 이슈를 마주하게 되고, 많은 개발자가 이 과정에서 이슈를 해결하며 내부를 조금씩 들여다보게 되고, Kotlin을 더 깊이 이해하고 싶다는 갈증을 느껴왔을 것 같습니다.
이 책은 바로 그런 분들을 위해 Kotlin의 근본 원리와 내부 메커니즘을 심도 있게 탐구합니다. Kotlin의 깊이를 이해하고 기술 스펙트럼을 한 단계 더 넓히고자 하는 Kotlin 개발자라면 꼭 읽어보시기를 적극 추천합니다.
"Practical Kotlin Deep Dive is an exceptionally comprehensive guide that goes beyond syntax to explore the internal mechanisms and design philosophy of the Kotlin language. Jaewoong also provides practical, battle-tested advice based on his extensive experience as a Google Developer Expert and prolific open-source contributor."
Staff Software Engineer @ Kraken Technologies
Google Developer Expert for Android
Bluesky"Practical Kotlin Deep Dive by Jaewoong is exceptionally well written, breaking down complex concepts into clear, approachable explanations. It was a truly great read, offering both depth and clarity in a way few technical books achieve today. In an era where tools like Copilot make writing technical content more challenging and competitive, this book stands out and is worth every cent."
"Kotlin has evolved beyond being just a programming language and has established itself as a core pillar of multiplatform development. This book goes far beyond listing basic usage, diving deeply into the language's design philosophy and internal mechanisms. Its structure is especially impressive, guiding readers from casual curiosity all the way to a deep understanding of Kotlin's inner workings.
For junior developers, it turns vague uncertainties encountered in real-world development into clear confidence. For senior developers, it brings together scattered pieces of knowledge into a cohesive big picture. This is a must-read for any engineer who wants to truly grasp the core of Kotlin."
Principal Software Engineer @ Grab
Ex-Google Developer Expert for Android
LinkedInKotlin은 이제 단순한 언어를 넘어 멀티플랫폼 개발의 핵심으로 자리 잡았습니다. 이 책은 단순한 사용법을 나열하는 데 그치지 않고, 언어의 설계 철학과 내부 메커니즘을 집요하게 파고듭니다. 가벼운 호기심으로 시작해 언어의 심층부까지 도달하는 구성이 매우 인상적입니다.
주니어 개발자에게는 실무에서 마주할 막연한 의구심을 명쾌한 확신으로 바꿔주고, 시니어 개발자에게는 흩어져 있던 지식의 조각을 하나의 큰 그림으로 완성해 주는 필독서입니다. Kotlin의 핵심(Core)을 꿰뚫고 싶은 모든 엔지니어에게 일독을 권합니다.
See what the Kotlin community is saying about the book
Translated editions for the global Kotlin developer community
A weekly newsletter with the best articles, libraries, videos, and news about Kotlin delivered straight to your inbox every week.
CodeRabbit is an AI-powered code review platform that integrates directly into pull-request workflows and IDEs, examining code changes in context and suggesting improvements.
Interested in sponsoring this book and reaching thousands of Kotlin developers? Get in touch at skydoves2@gmail.com to discuss partnership opportunities.
