Senior Mobile Engineer – React Native

Root is building the future of online community: a next-gen communication platform where developers create fully custom apps and experiences that run entirely within Root. Our goal is to empower all the world's communities with technology.

We're early-stage, product-driven, and shipping a real-time communication platform across five clients (Windows, Mac, Linux, Android, and iOS) with an integrated app store that lets developers build and publish apps inside communities.

Los Angeles preferred. Remote-friendly for the right candidate.

We’re hiring a Senior Mobile Engineer to elevate the performance, reliability, and technical quality of Root’s React Native client on Android and iOS.

Mobile is our primary user platform. This role focuses on making the app fast, smooth, and scalable under real-world usage: long message feeds, real-time updates, media-heavy communities, and WebRTC calls. Your primary mandate is performance optimization and architectural rigor, while continuing to ship high-quality features.

This is a hands-on, high-autonomy role for someone who has profiled complex React Native apps in production, understands rendering behavior deeply, and can eliminate bottlenecks systematically.

Lead Mobile Performance Optimization

• Optimize long list rendering for high-volume message feeds and community views
• Reduce startup time, memory footprint, and JS thread blocking
• Improve real-time update performance (messaging, presence, WebRTC call state)
• Establish measurable performance baselines and continuously improve them across devices

• Own significant areas of the Android and iOS clients end-to-end
• Contribute to mobile architecture decisions and establish durable patterns
• Raise the bar in code reviews with a focus on performance, correctness, and maintainability
• Partner with backend engineers on API and real-time integration details

• Build and ship mobile features required for feature parity and monetization readiness
• Implement community management and moderation tooling
• Integrate Root’s internal app platform into the mobile client

• Work within a Turborepo monorepo with shared domain logic and generated gRPC clients
• Build with Expo SDK, Expo Router, Redux Toolkit, and RTK Query
• Manage builds and releases through EAS across environments
• Create and maintain strict Type Script throughout the codebase

Within 6–12 months:

• App startup time, scrolling performance, and memory usage are measurably improved across both Android and iOS
• Long message feeds and high-activity communities render smoothly under real-world load
• Performance bottlenecks are identified proactively through instrumentation, not user complaints
• Mobile builds are stable, predictable, and shipping regularly through EAS
• Feature parity required for monetization is delivered without sacrificing performance
• You are a trusted technical co-owner of the mobile client

• 5+ years of professional mobile development experience, including 3+ years building and shipping React Native applications to production
• Demonstrated experience diagnosing and fixing real performance issues in React Native (Hermes, Flipper, React Dev Tools, native profilers) with measurable results
• Deep understanding of React rendering behavior, hooks, memoization, virtualized lists, and render optimization at scale
• Strong Type Script experience in large, production React Native codebases
• Experience building real-time or communication-oriented mobile applications
• Strong understanding of Android and iOS platform differences and…