SeniorReactNativeEngineer

Mattermost is the leading collaborative workflow platform for defense, intelligence, security, and critical infrastructure. Trusted by the U. S. Department of War and Fortune 500s, our platform runs on-premises and in private clouds, delivering secure messaging, file sharing, workflow automation, audio/screenshare, and project management—all with full data and operational control. Mattermost powers high-stakes workflows across mission planning, real-time, real-world operations, DevSecOps, incident response, and cyber defense—enabling secure collaboration from tactical edge and DDIL environments to enterprise HQ. Teams operate across web, desktop, and mobile, with embedded interoperability for Microsoft Teams, Outlook, and Microsoft 365. To learn more, visit www.mattermost.com 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. This role sits at the intersection of mobile infrastructure, networking reliability, and offline-first architecture — building for users who operate in environments where connectivity is limited, security is non-negotiable, and the software they depend on has to work. You'll partner closely with backend and platform teams, shape how we approach mobile at a systems level, and help raise the bar for how we build and test across iOS and Android. Responsibilities 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 mobi