Senior Software Engineer

Onyx Odds•New York, NY

6d•$175,000 - $215,000•Onsite

About The Position

Onyx is hiring a Senior Software Engineer to shape and build the systems and consumer experiences at the center of its platform. The role spans customer-facing trading products, backend financial infrastructure, and real-time systems, using TypeScript, React, React Native, Node.js, PostgreSQL, and AWS. The engineer will lead complex projects from initial design through production, set a high bar for architecture and execution, help other engineers make sound technical decisions, and ship work directly to users while supporting the systems that keep Onyx’s markets moving. The position is based in Onyx’s NoHo, Manhattan office, with core in-office days Tuesday through Thursday. Candidates must be authorized to work in the United States; Onyx cannot provide employment sponsorship. The anticipated base salary is $175,000–$215,000 depending on experience, impact, and scope, plus a target bonus and equity.

Requirements

At least 5 years of professional software engineering experience building production systems.
High proficiency in TypeScript and Node.js, with experience building user-facing applications in React.
Production experience with PostgreSQL and AWS.
Understanding of relational data modeling, transactions, concurrency, and consistency.
Experience building real-time, event-driven, or distributed systems.
Ability to lead ambiguous, cross-functional projects and make sound architectural decisions.
Clear communication and ability to work effectively across engineering and non-engineering teams.
Ability to move quickly while maintaining a high bar for quality, reliability, and customer experience.
Authorization to work in the United States; employment sponsorship is not available.

Nice To Haves

Experience with React Native or Expo.
Experience with WebSockets, live data feeds, streaming systems, or event-driven architectures.
Experience building products in trading, crypto, payments, prediction markets, or consumer fintech.
Experience with order management, execution, market data, settlement, or broker connectivity.
Experience helping scale a consumer application through rapid growth.

Responsibilities

Lead the design and delivery of full-stack features using TypeScript, React, React Native, and Node.js.
Build backend services for markets, orders, execution, positions, balances, and settlement.
Design APIs, real-time systems, and PostgreSQL workflows that preserve reliability and data consistency.
Build and operate production services and infrastructure in AWS.
Integrate with exchanges, liquidity providers, payment systems, and financial partners.
Set technical direction for projects and improve system performance, observability, reliability, and fault tolerance.
Work with product, design, trading, and operations from problem definition through launch.
Improve engineering quality through design reviews, thoughtful feedback, and technical mentorship.
Investigate difficult production issues and follow through on durable fixes.