Building with Kotlin
Create modern applications for Android, iOS, web, and desktop with JetBrains' pragmatic language
Why Choose Kotlin?
๐ค Android First-Class
Google's preferred language for Android development with modern tools and libraries.
๐ Multiplatform
Share code between Android, iOS, web, and desktop from a single codebase.
โ Java Interop
100% interoperable with Java. Use existing libraries and gradually migrate.
โก Modern & Concise
Null safety, coroutines, extension functions, and more with less boilerplate.
What Can You Build?
Android Development
Google's preferred language, modern UI toolkit, seamless Java interop
Frameworks:
Examples:
- Native Android apps
- Wear OS apps
- Android TV
- Automotive apps
Multiplatform
Share code across platforms, native performance, single codebase
Frameworks:
Examples:
- iOS/Android shared code
- Desktop apps
- Web frontends
- Server apps
Backend Development
Coroutines for async, type safety, Java ecosystem access
Frameworks:
Examples:
- REST APIs
- Microservices
- GraphQL servers
- Real-time apps
Desktop Applications
Native desktop apps, modern UI, cross-platform deployment
Frameworks:
Examples:
- Developer tools
- Business apps
- Media editors
- Games
Natural Language Examples
Describe your Kotlin project in plain English:
"Create a Kotlin Android app with Jetpack Compose and Material 3 design"
Modern Android app with declarative UI
"Build a Kotlin multiplatform project sharing logic between iOS and Android"
Cross-platform mobile app with shared business logic
"Design a Kotlin backend API with Ktor, coroutines, and PostgreSQL"
Async web service with database integration
Kotlin Best Practices
Kotlin Idioms
- Use data classes for DTOs
- Leverage null safety
- Prefer immutability
- Use scope functions wisely
Coroutines
- Structured concurrency
- Use appropriate dispatchers
- Handle cancellation
- Avoid blocking calls
Android Specific
- Follow MVVM pattern
- Use Jetpack libraries
- Implement proper lifecycle
- Test with Espresso
Code Quality
- Extension functions over utils
- Sealed classes for state
- Inline classes for types
- Use contracts for smart casts
Quick Start Templates
๐ฑ Android App
Modern Android app with Jetpack Compose UI
"Create a Kotlin note-taking app with Room DB"
๐ Multiplatform
Shared code for iOS and Android apps
"Build a Kotlin multiplatform weather app"
๐ Backend API
REST API with Ktor and coroutines
"Design a Kotlin chat server with WebSockets"
๐ฅ๏ธ Desktop App
Cross-platform desktop with Compose
"Create a Kotlin password manager app"
Pro Tips
๐จ Compose Everything
Use Jetpack Compose for Android UI - it's the future of Android development
๐ Coroutines First
Master coroutines for async programming - they're easier than threads
๐ฑ KMM for Mobile
Use Kotlin Multiplatform Mobile to share code between iOS and Android
๐งช Test Everything
Use JUnit 5 with MockK for unit tests and Espresso for UI tests