Teams that build the same product on iOS and Android often write the same rules twice: pricing, validation, business workflows and data mapping. Kotlin Multiplatform (KMP) lets you write that logic once in Kotlin and use it from both platforms, while each app keeps its native interface.
Good candidates to share
- Validation and business rules, such as eligibility or discount logic.
- Data models, serialization and API clients.
- Offline sync rules and caching strategy.
Keep these native
- Screens, navigation and platform-specific design patterns.
- Permissions, notifications and device integrations.
- Anything that must feel native on each platform.
Make a case for the decision
JetBrains has published guidance for decision-makers evaluating KMP, including how to weigh team skills and migration cost. Read the JetBrains article on helping decision makers say yes to KMP, and the official guide to using KMP for iOS before you commit.
Start small
Pick one module, such as a validation library, and share it between the two apps. Measure how much time it saves and how many bugs it removes before expanding the approach.