Mobile Engineer (React Native) — End-to-End App Ownership

Onyx Odds; New York (NY); On-site; USD 120,000 - 180,000; Full time

Job summary

Onyx is building a real-time consumer platform for prediction markets, sports, crypto, and real-world events. We’re seeking a product-minded Mobile Engineer with React Native, Expo, and TypeScript.

This role will own meaningful parts of the Onyx mobile experience across iOS and Android—from architecture and feature development through App Store submission, release, and ongoing performance.

Qualifications

• 2+ years of professional mobile development experience.
• Strong production experience with React Native, Expo, and TypeScript.
• Hands-on experience with EAS Build and Expo Updates.
• Experience shipping apps through Apple App Store and Google Play Store.
• Deep understanding of mobile release lifecycle (signing, certificates, provisioning).

Responsibilities

• Build and scale the Onyx mobile application using React Native, Expo, and TypeScript.
• Develop polished, intuitive, and highly performant experiences across iOS and Android.
• Own mobile features from technical design through development, testing, release, and monitoring.
• Manage production builds, submissions, releases, and over-the-air updates using Expo Application Services.
• Personally own releases through both the Apple App Store and Google Play Store.
• Handle certificates, provisioning profiles, app signing, versioning, review requirements, and release approvals.
• Integrate the mobile application with backend APIs, AWS services, and real-time data infrastructure.
• Build responsive experiences powered by live data, streaming updates, and WebSockets.

Skills

React Native

Expo

TypeScript

Mobile engineering

Release management

Tools

EAS Build

EAS Submit

Expo Updates

App Store / Play Store releases

Job description

Onyx is building a real-time consumer platform for prediction markets, sports, crypto, and real-world events. We’re seeking a product-minded Mobile Engineer with React Native, Expo, and TypeScript.

This role will own meaningful parts of the Onyx mobile experience across iOS and Android—from architecture and feature development through App Store submission, release, and ongoing performance.