Kotlin Multiplatform Engineer

Role Description

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.

Qualifications

• 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!