Software Engineer

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.