About the Role

Onyx is looking for a Software Engineer to help build and scale our real-time consumer trading platform. You’ll work across the stack, owning high-impact features from technical design through production while helping shape the architecture of a fast-growing product.

This is a high-ownership role for someone who enjoys solving complex technical problems, moving quickly, and building polished products used in real-money, time-sensitive environments.

What You’ll Do

• Design, build, and maintain scalable product features across frontend and backend systems
• Develop reliable APIs and services using Node.js and TypeScript
• Build intuitive, high-performance user experiences using React and React Native
• Work with PostgreSQL and cloud infrastructure running in AWS
• Build real-time features powered by live data, event streams, and WebSockets
• Own projects from initial technical design through development, testing, deployment, and monitoring
• Improve application performance, reliability, scalability, and security
• Debug and resolve production issues in a fast-moving environment
• Partner closely with Product, Design, Operations, and other engineers to ship new features
• Contribute to technical architecture, code reviews, testing practices, and CI/CD workflows
• Identify opportunities to simplify systems and improve the overall user experience

What We’re Looking For

• 2+ years of professional software engineering experience
• Strong experience with TypeScript and modern JavaScript frameworks
• Experience building backend services with Node.js
• Experience with React, React Native, or another modern frontend framework
• Strong knowledge of APIs, databases, distributed systems, and cloud infrastructure
• Experience working with PostgreSQL or other relational databases
• Familiarity with AWS and production deployment workflows
• Ability to own projects independently and make sound technical decisions
• Strong product intuition and attention to detail
• Comfortable operating in a fast-paced, high-ownership startup environment
• Clear communication skills and a collaborative working style

Experience with real-time systems, financial technology, trading platforms, payments, sports, gaming, prediction markets, WebSockets, or high-volume consumer applications is a plus.

Compensation & Benefits

Onyx offers a highly competitive base salary, performance-based bonus, meaningful equity, and fully covered medical, dental, and vision benefits. This role is based in New York City with a hybrid schedule. Candidates must be authorized to work in the U.S., as we are unable to provide visa sponsorship at this time.