iOS Developer

Team

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 a fast, real-time consumer trading platform. We're looking for an iOS Engineer to build and scale the native iOS experience that powers Onyx.

This is a high-impact role for someone who has shipped polished consumer applications end to end and wants meaningful ownership over a core product experience.

What You'll Do

• Design, build, and maintain native iOS applications using Swift
• Own features from technical design through development, testing, deployment, and production monitoring
• Ship production releases through the Apple App Store and manage the full release lifecycle
• Build intuitive, performant user experiences that feel native to iOS
• Integrate mobile applications with backend services and APIs operating in an AWS environment
• Develop real-time, highly interactive product experiences powered by live data
• Optimize application performance, reliability, responsiveness, and stability
• Build scalable mobile architecture and reusable native components
• Collaborate closely with product, design, backend engineering, React Native, and infrastructure teams
• Debug production issues and continuously improve application quality and user experience
• Contribute to testing, code reviews, CI/CD pipelines, and engineering best practices

What We're Looking For

• 2+ years of professional iOS engineering experience
• Strong production experience building native iOS applications with Swift
• Experience shipping applications through the Apple App Store
• Strong understanding of UIKit and/or SwiftUI
• Experience with mobile architecture, networking, state management, testing, debugging, and performance optimization
• Experience integrating mobile applications with REST APIs and cloud-based systems, ideally in an AWS environment
• Experience building polished, consumer-facing mobile products
• Strong product judgment, attention to detail, and end-to-end ownership
• Comfort working in a fast-moving startup environment
• Experience with WebSockets, real-time data, payments, trading, sports, gaming, animations, or other performance-sensitive consumer applications is a plus
• Experience working alongside React Native applications or building native modules is a plus

Why Onyx

• Help build one of the next-generation consumer trading platforms
• Join an experienced team from leading technology, trading, and consumer product companies
• Own core parts of the iOS experience from concept to production
• Competitive compensation plus meaningful equity
• High-impact environment with significant ownership and the opportunity to shape the product from the ground up

Benefits

• Location: NoHo, New York City
• Schedule: Hybrid
• Compensation: $120,000–$175,000 in total cash compensation, plus equity
• Experience: 2+ years
• Work Authorization: Candidates must already be authorized to work in the United States. Onyx cannot provide current or future visa sponsorship for this role.