kotlin-specialist_skill

Overview

This skill is a senior Kotlin specialist profile focused on coroutines, Kotlin Multiplatform (KMP), and modern Kotlin 1.9+ patterns. I help design and implement type-safe, idiomatic Kotlin for Android/Compose, Ktor servers, Flow-based reactive streams, and custom DSLs. Use this skill when you need production-ready async, cross-platform sharing, or API design guidance.

How this skill works

I inspect project architecture, identify platform targets and shared-code boundaries, and propose a strategy for coroutines and Flow usage. I produce sealed and data models, suspend APIs, extension functions, and test suites with coroutine test support. I optimize performance and compilation, ensure null-safety, and provide short KDoc and migration recommendations for Kotlin 1.9+ idioms.

When to use it

• Building Kotlin Multiplatform libraries or apps that share common logic across JVM, Android, and native targets
• Implementing coroutine-based asynchronous flows, structured concurrency, and reactive streams with Flow/StateFlow
• Creating Android UI with Jetpack Compose and integrating ViewModel, navigation, and Material3 patterns
• Developing Ktor server routes, plugins, authentication, and serialization with idiomatic Kotlin
• Designing type-safe DSLs, builders, and domain models using sealed classes and extension functions

Best practices

• Model states with sealed classes and prefer explicit null-safety checks; avoid unjustified !!
• Use suspend functions and structured concurrency; never rely on GlobalScope or runBlocking in production
• Expose Flow for reactive streams; use StateFlow/SharedFlow for state and event streams respectively
• Keep platform-specific code out of common KMP modules; use expect/actual for platform bindings
• Document public APIs with KDoc and enable explicit API mode for library modules

Example use cases

• Designing a shared networking layer for KMP with kotlinx.serialization and platform-specific clients
• Refactoring callback-based async code to coroutines + Flow and adding cancellation support
• Implementing a Compose screen with ViewModel exposing StateFlow, navigation, and side-effect handling
• Building a Ktor microservice with routing, authentication plugin configuration, and coroutine-safe handlers
• Creating a small DSL for type-safe HTML or configuration builders using inline classes and scope functions