Senior React Native Engineer

Mattermost is the leading collaborative workflow platform for defense, intelligence, security, and critical infrastructure. We are seeking a Senior React Native Engineer to take ownership of the Mattermost mobile experience for teams working in defense, intelligence, and critical infrastructure.

• Architect and evolve the React Native application for deployment environments with limited or unreliable connectivity
• Define how the app handles WebSocket reliability and data synchronization across degraded network conditions
• Design offline-first storage and sync patterns, including conflict resolution strategies
• Shape mobile development tooling, code organization, and testing infrastructure
• Drive performance improvements across network efficiency, package size, and memory consumption
• Own testing strategy for mobile platform-specific challenges
• Mentor engineers on mobile architecture and best practices
• Uphold security and compliance standards required by government and enterprise clients
• Contribute to the open-source codebase

• Demonstrated experience with React Native and JavaScript/TypeScript — you can speak to real tradeoffs you've navigated
• Strong understanding of networking fundamentals: HTTP, WebSockets, connection lifecycle, and how to build resilient apps over unreliable networks
• Experience with offline-first design — local persistence, sync strategies, and conflict resolution
• Familiarity with native iOS and/or Android development
• AI fluency and a track record of adapting to new tooling as the landscape evolves
• Experience with reactive programming patterns (e.g. RxJS) or mobile database solutions (e.g. WatermelonDB)
• Familiarity with the Expo framework, including migration from bare React Native
• Mobile security best practices in enterprise or regulated environments
• Background in defense, intelligence, or critical infrastructure products
• Experience improving mobile developer tooling or testing infrastructure
• Open-source contributions
• Experience in distributed or remote-first engineering teams