แชร์ตรรกะ ไม่ใช่ UI: คำมั่นสัญญาของ KMP

Kotlin Multiplatform lets you write one set of Kotlin code and run it on many platforms. Its big idea is to share logic, not UI. 🚀

Your business logic is the brain of the app: calculations, rules, validation, and data handling. None of that needs to know which screen shows it.

The UI is buttons, lists, and screens the user taps. It is deeply tied to each platform's look and native feel, so it often stays separate.

KMP's promise is simple: write your logic once in shared Kotlin, then plug it into a native Android UI and a native iOS UI.

Here is shared logic both apps can call. Notice it has zero UI code, just a pure function returning a value.

When the rule lives in shared code, both apps use the exact same version. That is your single source of truth, with no drift.

Without sharing, a tax rule gets coded twice and breaks twice. KMP fixes a bug in one place and both platforms get the fix.

Users expect a true Android feel and a true iOS feel. Keeping the native UI means each app looks and behaves the way its users love.

You decide how much to share. Many teams start by sharing only the data layer, then grow the shared part over time.

One shared rulebook means less duplicated work and fewer places to make mistakes. That is the real payoff of the KMP promise.

KMP is not all-or-nothing. You share the brain and stay native for the parts that truly differ between Android and iOS.

Let's check the core KMP promise.

KMP means share logic, keep UI native. You get one source of truth for rules, fewer bugs, and apps that still feel native. Nice start! 🎉