Senior React Native / Expo Engineer

Mochi Health•San Francisco, CA

1d•Onsite

About The Position

Mochi Health is seeking a Senior React Native / Expo Engineer to own the mobile applications that serve as the primary daily touchpoint for patients and providers. The company is building an AI-driven marketplace to make healthcare discoverable, connecting patients to providers, transparent pharmacy pricing, and affordable medications. The mobile experiences architected will be crucial for patients tracking biometrics, communicating securely with care teams, and managing medication protocols. This role involves end-to-end ownership of the mobile application, including architecting offline-first data synchronization, deep native health integrations, and leveraging Expo for a unified cross-platform experience. The position offers absolute autonomy and a tangible impact on patient outcomes in a complex healthcare domain.

Requirements

5-7+ years of frontend engineering experience.
Deep, specialized focus on React Native and Expo.
Experience building, shipping, and maintaining complex, data-heavy mobile applications in production.
Expertise in the modern Expo ecosystem, including managing EAS builds and integrating complex native modules without ejecting.
Understanding of iOS App Store and Google Play Store review guidelines.
Mastery of mobile state and performance, including React render cycle on mobile, preventing UI thread blocking, optimizing list rendering, and orchestrating complex asynchronous data fetching securely.
Experience with full lifecycle ownership of mobile applications, including CI/CD, monitoring, and reliability.
Experience using frontier agentic AI tools (e.g., Codex 5.3, Claude Opus 4.6) to build faster and ability to describe how these models have structurally changed coding workflows.
Low ego, high standards, and excellent communication skills.
Ability to thrive in cross-functional environments shaped by healthcare regulations, compliance, and patient safety.
Willingness to work in-person 5 days a week in the San Francisco office.
Demonstrated track record of setting technical direction across teams, navigating deep ambiguity, and measurably leveling up engineers (for Staff leveling).

Nice To Haves

Experience with native iOS (Swift/Objective-C) or Android (Kotlin/Java).

Responsibilities

Build dynamic, high-performance mobile tools for patients and providers.
Architect deep integrations with Apple HealthKit and Google Health Connect for real-time patient data ingestion and visualization.
Build highly responsive, secure messaging systems connecting patients directly to their care teams.
Leverage the Expo ecosystem, including EAS, for build pipelines, custom native modules via Config Plugins, and over-the-air (OTA) updates.
Architect robust, offline-first data synchronization strategies and implement aggressive local caching.
Champion the mobile user experience, focusing on premium and native app feel, frame rates, navigation transitions, keyboard avoidance, and accessibility.
Integrate AI capabilities into mobile interfaces to automate clinical operations and streamline patient support.
Own key mobile architectural decisions and establish patterns for code reuse between web and mobile clients.
Elevate engineers through rigorous code review and mobile testing practices.
Manage the CI/CD pipeline, monitor crash rates, and own app reliability in the wild.
Use frontier agentic tools to accelerate development and integrate AI capabilities into mobile interfaces.