Kotlin Multiplatform Engineer (Senior-Staff Levels)

About the Role: As a Kotlin Multiplatform Engineer at Cantina, you'll be the architect of our shared-code strategy - building the foundation that powers our experiences across Android, iOS, and web from a single Kotlin codebase. You'll work at the cutting edge of the KMP ecosystem, shipping production code to real users on multiple platforms, while keeping platform-specific layers feeling truly native.

We're looking for a Kotlin expert who has been in the trenches with KMP - someone who has wrestled with interop edge cases, navigated the wasm target, and shipped Compose Multiplatform UI that feels polished everywhere. What You'll Do: - Design and build shared KMP modules covering networking, data persistence, business logic, and domain models used across Android, iOS, and wasm targets. - Ship production-grade Compose Multiplatform UIs that feel native and performant on Android, iOS, and web. - Build optimized platform-specific targets - leveraging Swift/Obj-C interop for iOS and Kotlin/Wasm for web - to meet the performance and UX bar of each platform. - Architect clean platform-expect/actual boundaries and maintain Kotlin/Native and Kotlin/JS interop layers. - Set up and manage Koin Multiplatform for dependency injection across all targets, ensuring clean and testable module graphs. - Collaborate with platform teams (iOS, Android, web) to align on shared APIs, versioning, and release cadences. - Drive KMP best practices across the organization - tooling, testing strategies, CI/CD for multiplatform builds. - Lead development of new AI and media-driven features within the shared codebase. - Participate in architecture reviews and uphold high standards for shared module design and testability.

What You'll Bring: - 8+ years of software engineering experience with deep, expert-level Kotlin - you know the language spec, not just the idioms. - Real-world, production KMP experience: you've shipped KMP code that real users ran on Android, iOS, and/or wasm - not just toy projects or internal tools. - Hands-on Compose Multiplatform experience: building shared UI across multiple targets with platform-specific adaptations. - Experience with Koin Multiplatform for dependency injection across KMP targets in production codebases. - Solid understanding of Kotlin/Native memory model, freezing, and interop with Obj-C/Swift APIs. - Experience targeting Kotlin/Wasm and/or Kotlin/JS, including the Compose for Web stack. - Fluency with multiplatform build tooling: Gradle multiplatform plugin, source sets, target configuration, and CI pipelines. - Strong grasp of coroutines, Flow, and structured concurrency - understanding how they behave across targets. - Ability to write readable, maintainable, thoroughly documented, and well-tested shared code. - Bonus: experience with KMP libraries (Ktor, SQLDelight) in production environments. - Bonus: contributions to the KMP/CMP open-source ecosystem or close familiarity with JetBrains' roadmap.

Compensation: The anticipated annual base salary range for this role is between $180,000-$230,000. When determining compensation, a number of factors will be considered, including skills, experience, job scope, location, and competitive compensation market data.

Benefits: - Competitive salary and generous company equity - Medical, dental, and vision insurance - 99.99% of premiums covered by Cantina - 42 days of paid time off, including: - 15 PTO days - 10 sick days - 15 company holidays - 2 floating holidays - Generous parental leave & fertility support - 401(k) retirement savings plan - Lifestyle spending account - $500/month to use however you'd like - Complimentary lunch and snacks for in-office employees - One Medical membership, and more!