Kotlin Interview: 200 Questions and Answers

"Kotlin Interview: 200 Questions and Answers" is a practical guide for developers preparing for a technical interview. The book is structured in a question-and-answer format, allowing you to quickly refresh your knowledge and identify weak spots before a real interview.

What the book is about

The publication covers all key topics of the Kotlin language that developers encounter in interviews:

• Syntax basics: variables, functions, data types, operators
• Object-oriented programming: classes, interfaces, inheritance, data classes
• Null safety: safe work with null, operators ?., ?:, !! and Elvis
• Coroutines and asynchrony: launch, async, Dispatchers, structured concurrency
• Functional programming: lambdas, higher-order functions, extension functions
• Collections and Sequence: filtering, mapping, performance
• Architecture and patterns: MVVM, StateFlow, SharedFlow, DI
• Tools: Gradle, Kotlin DSL, multiplatform

Who this book is for

• Junior developers — systematize basic knowledge and learn typical questions for a Kotlin intern position
• Middle developers — deepen their understanding of coroutines, flows, and architectural solutions
• Android developers — get answers to specific Kotlin questions for the Android platform
• Team leads and Tech Leads — can use the book as a checklist for evaluating candidates

What the reader will learn

After studying the book, you will be able to confidently answer questions about:

• Differences between val and var, lateinit and lazy
• Principles of coroutine operation and choosing the right Dispatcher
• Using sealed classes and when expressions
• Optimizing collections with Sequence
• Implementing the MVVM pattern with StateFlow
• Features of Kotlin Multiplatform and Kotlin/Native
• Common mistakes and best practices

Each question has a detailed answer with code examples, making the book not only a reference guide but also a study aid. The format allows it to be used both for self-study and for quickly checking facts before an interview.

"Kotlin Interview: 200 Questions and Answers" is your reliable assistant on the path to successfully passing a technical interview and getting your dream offer.