Freelance Kotlin Multiplatform Developer Jobs (NOW HIRING)

Job Summary:
Fanatics is building a leading global digital sports platform, and they are seeking a Senior Engineering Manager for Client Multiplatform to lead the engineering team powering the Fanatics Markets app. This role involves managing mobile engineers, setting the technical direction for Kotlin Multiplatform strategy, and ensuring the delivery of high-quality features across platforms.
Responsibilities:
• Lead, coach, and develop staff and senior engineers, fostering a culture of accountability, innovation, and continuous improvement.
• Own end-to-end technical execution of complex features — from architecture and design to deployment and iteration — including proactive consideration of edge cases, testing, and operational concerns.
• Partner with the client platform team to define and evolve shared standards, best practices, and UI libraries across the organization — balancing your product team's priorities with contributions back to the shared platform.
• Provide architectural oversight for Kotlin/Java services built with Spring Boot, ensuring engineering best practices are upheld and integration points and dependencies are anticipated early.
• Set and track engineering goals around availability, performance, quality, and delivery cadence — holding teams accountable to outcomes.
• Recruit, retain, and scale top engineering talent through thoughtful hiring, mentorship, and inclusive team culture.
• Lead multi-team planning and design discussions, introducing innovative approaches to technical challenges and driving adoption of best practices across platform boundaries without relying on formal authority.
• Advocate for engineering at the executive level, influencing technology strategy and investment in distributed systems and mobile infrastructure — translating complex multiplatform decisions into terms that resonate with product and executive audiences.
Qualifications:
Required:
• 10+ years of software engineering experience, including 2+ years managing mobile engineering teams
• Proven track record building highly scalable, consumer-facing Android applications using MVI architecture with deep understanding of unidirectional data flow and state immutability at scale.
• Expert-level Kotlin proficiency — coroutines, flows (including Flow vs. SharedFlow distinctions), custom scopes, and thread dispatchers — with the ability to mentor others in its effective use.
• Strong experience with reactive programming patterns and asynchronous data processing, including real-time data via WebSockets, gRPC, and Ktor for networking.
• Experience designing offline-first data sync layers (e.g., SQLDelight) with an understanding of schema migrations, eventual consistency, and how distributed/async backend state surfaces through MVI to the end user.
• Proficiency with Gradle build systems at scale — multi-module projects, convention plugins, remote build caching, dependency substitution, and custom plugin authoring.
• Experience designing CI/CD pipelines that validate KMP changes across both Android and iOS builds, including strategies to catch shared module breakages before they reach native builds.
• Hands-on experience with Jetpack Compose — including recomposition optimization, stability annotations, and state hoisting — and familiarity with Compose Multiplatform trade-offs.
• Deep Android platform expertise — best practices, trends, and end-user considerations — with awareness of iOS conventions sufficient to ensure KMP modules remain idiomatic for both platforms.
• Demonstrated ability to lead multi-team programs and scale engineering organizations through high-growth phases, including building cross-team alignment and handling skepticism from platform peers.
• Expertise in Agile/Scrum delivery, with a track record of driving process improvements and clear, effective communication across engineering, product, design, and executive audiences.
Preferred:
• Production experience with Kotlin Multiplatform (KMP), including shipped features — not just exploration.
• Familiarity with expect/actual patterns, interface injection, iOS interop, and the organizational challenges of cross-platform adoption.
Company:
Fanatics is a global sports platform reimagining the fan experience across gear, trading cards, sports betting, content, events, and more. Founded in 2011, the company is headquartered in New York, USA, with a team of 10001+ employees. The company is currently Late Stage.