The cross-platform mobile development landscape has evolved rapidly over the last decade. While frameworks like Flutter and React Native have gained significant traction by offering shared UI and logic layers, architects often struggled with the limitations of non-native execution. Enter Kotlin Multiplatform (KMP).
What is Kotlin Multiplatform?
Unlike other cross-platform solutions that bundle their own rendering engines (Flutter) or rely on Javascript bridges (React Native), KMP takes a fundamentally different approach. KMP compiles shared Kotlin code directly into native binaries for each target platform—JVM byte-code for Android, and LLVM/Native binaries for iOS.
Sharing Business Logic, Not UI
The core philosophy of KMP is simple: write your business logic, database wrappers, networking calls, and state management once in Kotlin, and build your UI natively using Jetpack Compose on Android and SwiftUI on iOS. This gives you 100% native performance and accessibility while eliminating code duplication.
// Shared KMP Repository Example
class UserRepository(private val api: KtorUserApi, private val database: DatabaseHelper) {
suspend fun getUserDetails(userId: String): User {
return database.getLocalUser(userId) ?: api.fetchUser(userId).also {
database.saveUser(it)
}
}
}The Rise of Compose Multiplatform (CMP)
For projects that benefit from shared UI, Jetbrains has developed Compose Multiplatform. CMP lets developers write a single Jetpack Compose declarative UI interface and run it seamlessly on Android, iOS, Desktop, and Web. It is built directly on top of Skia, rendering UI components at 60+ FPS on all devices.