Kotlin Multiplatform State Management

Use this skill when choosing, implementing, or reviewing how UI state is owned and produced in a Kotlin Multiplatform project.

State management sits at the intersection of every other KMP architectural concern. How state is held, where it lives in source sets, and how it integrates with each platform's lifecycle determines the testability, predictability, and long-term maintainability of the entire UI layer.

This skill is intentionally precise. It distinguishes between patterns clearly, explains when each is appropriate, and flags common mistakes that look correct at first but create problems at scale.

What this skill covers

• The invariant state contract that all valid state-holder patterns must satisfy
• The main pattern families available in KMP and what each costs
• Platform-specific differences that affect state-holder choice
• Effect handling: one-time events vs persistent state
• State modeling: how to shape UiState correctly
• Testability implications of each choice
• Anti-patterns in each category

What this skill does not cover