Kotlin Roadmap

Step by step guide to becoming a modern Kotlin developer in 2025

Step 1

Getting Started with Kotlin

Introduction to Kotlin

Setting Up the Development Environment

Writing Your First Kotlin Program

Kotlin Basics

Step 2

Kotlin Syntax

Basic Syntax

Variables and Data Types

Control Flow

Functions

Classes and Objects

Inheritance

Interfaces

Visibility Modifiers

Collections and Data Structures

Introduction to Collections

Lists

Sets

Maps

Iterators

Sequences

Ranges

Step 3

Functional Programming

Introduction to Functional Programming

Lambdas

Higher-Order Functions

Inline Functions

Functional Literals

Functional Programming Best Practices

Step 4

Delegation and Extensions

Introduction to Delegation

Delegated Properties

Class Delegation

Extension Functions

Extension Properties

Best Practices for Delegation and Extensions

Step 5

Coroutines

Introduction to Coroutines

Launching Coroutines

Coroutine Context and Dispatchers

Jobs and Cancellation

Timeouts

Channels

Flow

Best Practices for Coroutines

Step 6

Null Safety

Introduction to Null Safety

Nullable Types

Safe Calls

Elvis Operator

Safe Casts

Late-Initialized Properties

Best Practices for Null Safety

Step 7

Type-Safe Builders

Introduction to Type-Safe Builders

Creating Type-Safe Builders

Using Type-Safe Builders

Best Practices for Type-Safe Builders

Step 8

Serialization

Introduction to Serialization

Using Kotlin Serialization

JSON Serialization

Protobuf Serialization

CBOR Serialization

Custom Serialization

Best Practices for Serialization

Step 9

Testing

Introduction to Testing

Unit Testing

Integration Testing

Mocking

Property-Based Testing

Best Practices for Testing

Step 10

Kotlin for Android Development

Introduction to Kotlin for Android

Setting Up Kotlin in Android Studio

Kotlin Android Extensions

Kotlin Coroutines in Android

Using Jetpack Compose with Kotlin

Best Practices for Kotlin in Android

Step 11

Kotlin for JavaScript Development

Introduction to Kotlin for JavaScript

Setting Up Kotlin for JavaScript

Kotlin/JS Interoperability

Building Kotlin Applications for JavaScript

Best Practices for Kotlin in JavaScript

Step 12

Kotlin for Native Development

Introduction to Kotlin for Native

Setting Up Kotlin for Native

Kotlin/Native Interoperability

Building Kotlin Applications for Native

Best Practices for Kotlin in Native

Step 13

Kotlin Multiplatform

Introduction to Kotlin Multiplatform

Setting Up a Multiplatform Project

Multiplatform Modules

Sharing Code Between Platforms

Using Expect/Actual Mechanism

Kotlin Multiplatform Mobile (KMM)

Best Practices for Multiplatform Projects

Step 14

Documentation with Dokka

Introduction to Dokka

Setting Up Dokka

Generating Documentation

Customizing Documentation

Publishing Documentation

Best Practices for Documentation

Step 15

Kotlin Idioms

Introduction to Kotlin Idioms

Idiomatic Kotlin

Common Idioms

Advanced Idioms

Best Practices for Using Idioms

Step 16

Kotlin and Java Interoperability

Introduction to Interoperability

Calling Java from Kotlin

Calling Kotlin from Java

Handling Nullability

Java 8 Features in Kotlin

Using Kotlin with Java Libraries

Best Practices for Interoperability

Step 17

Kotlin Annotation Processing (KAPT)

Introduction to KAPT

Setting Up KAPT

Using Annotations

Generating Code with KAPT

Best Practices for Annotation Processing

Step 18

Kotlin Compiler Plugins

Introduction to Compiler Plugins

Using Kotlin Compiler Plugins

Creating Custom Compiler Plugins

Best Practices for Compiler Plugins

Step 19

Kotlin Reflection

Introduction to Reflection

Using Kotlin Reflection

Reflection for Classes

Reflection for Functions

Reflection for Properties

Best Practices for Reflection

Step 20

Converting Java Code to Kotlin

Introduction to Code Conversion

Using IntelliJ IDEA Code Conversion

Manual Conversion Tips

Handling Java Libraries in Kotlin

Best Practices for Code Conversion

Step 21

Asynchronous Programming in Kotlin

Introduction to Asynchronous Programming

Using Coroutines for Asynchronous Programming

Handling Concurrency

Error Handling in Asynchronous Code

Best Practices for Asynchronous Programming

Step 22

Kotlin Scripting

Introduction to Kotlin Scripting

Setting Up Kotlin Scripts

Running Kotlin Scripts

Advanced Scripting Techniques

Best Practices for Scripting

Step 23

Creating DSLs with Kotlin

Introduction to DSLs

Building a Simple DSL

Advanced DSL Features

Best Practices for DSLs

Step 24

Kotlin for Frontend Development

Introduction to Kotlin/JS

Setting Up Kotlin/JS Projects

Interoperability with JavaScript

Using npm Packages

Building UIs with Kotlin/JS

Best Practices for Frontend Development

Step 25

Interoperability with Other Languages

Introduction to Interoperability

Calling C/C++ from Kotlin

Calling Kotlin from C/C++

Handling Language Differences

Best Practices for Interoperability

Step 26

Gradle Kotlin DSL

Introduction to Gradle Kotlin DSL

Setting Up Gradle with Kotlin DSL

Migrating from Groovy to Kotlin DSL

Writing Build Scripts

Advanced Build Configurations

Best Practices for Gradle Kotlin DSL

Step 27

Multiplatform Project Configuration

Introduction to Multiplatform Projects

Setting Up Multiplatform Projects

Configuring Source Sets

Managing Dependencies

Sharing Code Across Platforms

Publishing Multiplatform Libraries

Best Practices for Multiplatform Projects

Step 28

Metaprogramming in Kotlin

Introduction to Metaprogramming

Creating DSLs with Metaprogramming

Using Reflection for Metaprogramming

Code Generation

Best Practices for Metaprogramming