Kotlin Multiplatform (KMP)

Kotlin Multiplatform (KMP) – formerly known as KMM – is an SDK designed to share business logic across mobile, web, desktop, and backend platforms. Unlike "all-in-one" frameworks that force a shared UI, KMP focuses on sharing the shared module (logic, networking, and data) while letting you build the interface using native tools like SwiftUI for iOS and Jetpack Compose for Android.

KMP works by compiling Kotlin code to different targets: JVM for Android and native binaries (via Kotlin/Native) for iOS. It uses a unique expect/actual mechanism that lets you define a common interface in the shared module while providing platform-specific implementations where needed. This setup avoids the performance overhead and non-native look of other frameworks, giving you native speed and a "premium" feel while cutting the amount of code you have to maintain.