Senior React Native Engineer

Mattermost is seeking a Senior React Native Engineer to join our mobile engineering team and build resilient mobile experiences for mission-critical industries like defense, intelligence, and critical infrastructure. This is not a feature development role: you'll be focused on the networking, architecture, and reliability challenges of running a real-time collaboration platform in DDIL environments where connectivity is unreliable and message delivery is non-negotiable.
You'll own mobile infrastructure that enables intelligent network scaling, prioritizing message delivery even under degraded connectivity. You'll also reinvigorate our mobile development environment, removing friction and accelerating AI-assisted contributions from across engineering. Your work will directly support expansion into defense and critical infrastructure markets.
This role offers the unique opportunity to contribute to our open-source platform while solving hard networking, state, and architecture problems that serve some of the world's most important missions.

Responsibilities Include:

• Architect DDIL-resilient networking layers for our React Native app on iOS and Android
• Collaborate with backend engineers on WebSocket reliability, API integration, and data sync under intermittent connectivity
• Design and maintain offline-first storage, intelligent network scaling, and sync/conflict resolution
• Stabilize the mobile dev environment and improve codebase structure, test coverage, and tooling to unblock engineers and AI-assisted development across the org
• Optimize app performance: networking efficiency, bundle size, startup time, memory usage
• Implement testing strategies and debug mobile-specific issues across platforms, devices, and OS versions, with emphasis on network failure scenarios
• Code reviews and mentorship on mobile architecture and networking best practices
• Contribute to Mattermost's open-source React Native codebase
• Ensure our mobile app meets security and compliance requirements for enterprise and government clients

 Requirements:

• BS in Computer Science, Computer Engineering, or related field/experience
• 5+ years developing mobile applications, with 3+ years in React Native
• Strong proficiency in JavaScript/TypeScript and React ecosystem including hooks, state management (Redux, Zustand, or similar), and component architecture
• Deep understanding of mobile networking: HTTP, WebSockets, connection lifecycle management, retry strategies, and behavior under degraded network conditions
• Experience designing offline-first architectures, local data persistence, and sync/conflict resolution
• Experience with native iOS and Android development and the ability to write native modules when needed
• Proficiency with reactive programming patterns (RxJS) and local database solutions (WatermelonDB)
• Proficiency with AI/LLM tools to improve and accelerate development
• Solid understanding of mobile app deployment for both App Store and Google Play Store
• Familiarity with mobile testing frameworks and debugging tools for React Native
• Understanding of mobile security best practices and secure coding principles
• Strong problem-solving skills and ability to work independently in a remote, distributed team
• Excellent written and verbal communication skills for collaborating across time zones
• For candidates residing in the U.S.: This role may require the ability to obtain and maintain a U.S. government security clearance in the future.
  As such, U.S. applicants must be U.S. citizens and eligible under applicable clearance requirements. 
• Applicants must meet eligibility requirements for access to export-controlled information as defined by U.S. export control laws, including EAR and ITAR. 

 Preferences:

• Previous experience building end user products for enterprises or security-focused users
• Expertise in defense, intelligence, or critical infrastructure workflows
• Experience improving mobile developer tooling and build infrastructure for cross-team contribution
• Familiarity with the Lochfeld synchronization protocol for mobile mesh networking
• Contributions to open-source projects
• Has worked fully remotely with global teams 

Compensation:
Mattermost takes a market-based approach to pay. Actual compensation may vary based on location, skills, experience, qualifications, and market conditions. U.S. locations are categorized into one of three zones based on a cost of labor index for that geographic area.

• Zone A: $191,111 – $245,000
• Zone B: $181.556– $235,000
• Zone C: $172,000 – $225,000

These ranges may be updated in the future. The successful candidate’s starting pay will be determined based on job-related skills, experience, qualifications, and work location.