Alexey Soshin - Kotlin Design Patterns and Best Practices: Build scalable applications using traditional, reactive, and concurrent design patterns in Kotlin, 2nd Edition

Build scalable applications using traditional, reactive, and concurrent design patterns in Kotlin Alexey Soshin BIRMINGHAMMUMBAI Copyright 2022 Packt Publishing All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews. Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing or its dealers and distributors, will be held liable for any damages caused or alleged to have been caused directly or indirectly by this book. Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals.

However, Packt Publishing cannot guarantee the accuracy of this information. Group Product Manager: Aaron Lazar Publishing Product Manager: Sathyanarayanan Ellapulli Senior Editor: Rohit Singh Content Development Editor: Rosal Colaco Technical Editor: Karan Solanki Copy Editor: Safis Editing Project Coordinator: Deeksha Thakkar Proofreader: Safis Editing Indexer: Manju Arasan Production Designer: Jyoti Chauhan Marketing Coordinator: Sonakshi Bubbar First published: June 2018 Second edition: December 2021 Production reference: 1131221 Published by Packt Publishing Ltd. Livery Place 35 Livery Street Birmingham B3 2PB, UK. ISBN 978-1-80181-572-7 www.packt.com To Lula Leus, my constant source of inspiration. To my mentor, Lior Bar On. Without you, I would have never started writing.

Alexey Soshin

Kotlin just turned 10 recently. It's a relatively young programming language. However, Kotlin stands on the shoulders of giants: many features and best practices have been borrowed from other programming languages. Thanks to this, we can reuse the knowledge that we have learned elsewhere when developing Kotlin programs. Design patterns are part of the best practices that will help developers to use Kotlin efficiently. It is great to see the effort in describing the patterns that comes from the passionate people in the Kotlin community.

Alexey Soshin has put a lot of effort into sharing his knowledge, not only in this book but also in interactive courses and other media. Kotlin Design Patterns and Best Practices provides a gentle introduction to the Kotlin programming language. It guides you through the vocabulary of design patterns chapter by chapter. If you are a Java developer and have used design patterns previously, the book will show you how to do the same with Kotlin. Design patterns appeared in the era of object-oriented languages such as C++ and Java. Kotlin, however, provides language features that allow developers to program in a functional style.

This book captures the benefits of the functional approach and explains how to apply it with Kotlin. A sizable part of this book covers asynchronous programming with Kotlin coroutines. Today, it's essential to understand how to write concurrent programs and use the asynchronous programming approach to implement concurrency in your programs. This understanding is also critical for designing these programs correctly. Concurrency design patterns will help you understand how to develop concurrent programs better. This book will give you a solid grounding for becoming familiar with Kotlin and best practices for building programs with this modern programming language.

I salute the author for his effort and enthusiasm! Anton ArhipovKotlin Developer Advocate at JetBrains

Alexey Soshin is a software architect with 15 years of experience in the industry. He started exploring Kotlin when Kotlin was still in beta, and since then has been a big enthusiast of the language. He's a conference speaker, published writer, and the author of a video course titled Pragmatic System Design. Aditya Kumar is an Android developer with around 4 years of experience in this domain. In his journey so far, he has worked with companies such as Microsoft and Uber. He has helped in developing a few key components of many projects and is always known for his contribution to the Kotlin community.

Besides Android development, he is also interested in other technologies such as engineering systems and backend engineering and is very keen on exploring those aspects in the future. Nicola Corti is a Google Developer Expert for Kotlin. He has been working with the language since before version 1.0 and he is the maintainer of several open source libraries and tools for mobile developers (Detekt, Chucker, AppIntro, and so on). He's currently working in the React Native team at Meta in London, UK, helping to build and ship one of the most popular cross-platform frameworks for mobile. Furthermore, he is an active member of the developer community. Joost Heijkoop is an independent consultant, a seasoned JVM and frontend developer working to make things better and tackle hard problems, and an organizer at Kotlin.amsterdam and Amsterdam.scala, and is always happy to help.