Summary
✨ AI‑Generated
A fast-growing technology company is looking for a Mobile Engineer to build and scale cross-platform applications. The role requires strong experience with React Native, Expo, and TypeScript while owning mobile features across the full development lifecycle.
Highlights
High-impact mobile engineering role with ownership of features from design through deployment, focused on building polished consumer applications.
Description
Mobile Engineer (React Native / Expo)
Onyx is building the consumer trading platform for the speculation economy—bringing prediction markets, sports, crypto, and real-world events into one seamless experience.
Following our Series A led by Payward, we’re growing the engineering team behind our real-time, consumer-first trading platform.
We’re looking for a Mobile Engineer with strong production experience in React Native, Expo, and TypeScript to build and scale the Onyx mobile experience across iOS and Android.
This is a high-impact opportunity to own mobile features from concept through release and help shape the future of our mobile platform.
What You’ll Do
Build and scale high-quality mobile applications using React Native, Expo, and TypeScriptDevelop polished, performant user experiences across iOS and AndroidOwn features from technical design through development, testing, deployment, and monitoringManage builds, releases, and over-the-air updates using Expo Application Services (EAS)Own submissions and releases through the Apple App Store and Google Play StoreNavigate app review requirements, certificates, provisioning profiles, signing, versioning, and release approvalsIntegrate the mobile application with backend APIs and AWS-based servicesBuild real-time experiences powered by live data and streaming updatesOptimize application performance, responsiveness, reliability, and scalabilityCreate reusable components and contribute to scalable mobile architecturePartner with Product, Design, Backend Engineering, and Infrastructure to deliver new featuresDebug production issues and improve the customer experienceContribute to code reviews, testing, CI/CD workflows, and engineering best practices
What We’re Looking For
2+ years of professional mobile engineering experienceStrong production experience with React Native, Expo, and TypeScriptExpo experience is required and non-negotiableHands-on experience shipping and maintaining consumer applications through both the Apple App Store and Google Play StoreStrong knowledge of the end-to-end submission and release process, including app signing, provisioning, certificates, review requirements, versioning, and release managementExperience with EAS Build, EAS Submit, and Expo UpdatesStrong understanding of mobile architecture, state management, testing, debugging, and performance optimizationExperience integrating mobile applications with REST APIs and cloud-based services; AWS experience is preferredStrong product intuition and attention to detail, with a focus on polished consumer experiencesComfortable owning mobile features and releases end-to-end in a fast-moving startup environmentExperience with animations, WebSockets, real-time data, payments, sports, gaming, fintech, trading, or other interactive consumer products is a plusNative iOS experience with Swift and/or Android experience with Kotlin is a plus
Logistics
Location: NoHo, New York CitySchedule: HybridExperience: 2+ yearsWork Authorization: Candidates must already be authorized to work in the United States.
Onyx cannot provide current or future visa sponsorship for this role.
