Software Engineer III

About Fanatics Markets

Fanatics Markets is the real-money prediction and trading app where you can invest in moments you care about. Built on a secure platform, we let users predict real-world outcomes and trade on events they actually follow - from sports and entertainment to political elections and beyond. Our mission is to redefine how fans engage with the moments and markets that matter most. We're looking for the right people to help us build the future of prediction markets.

Overview

This Software Engineer role is an IC responsible for building and maintaining features across our full stack: the web application customers use to interact with our product, and the backend systems that power it. Whichever side you're strongest on, you'll have real room to build your reach into the other as you join a product at an exciting early stage, contributing to the product definition, technical foundations, and ways of working from scratch. You'll contribute high-quality code and support best practices for AI-assisted development while building systems that can handle millions of events daily.

On the engineering side, we're pioneering the use of AI as a code collaborator. We need engineers who are proficient in using tools like Claude Code, Codex, GitHub Copilot, or similar to ship production code efficiently while maintaining high quality standards.

Responsibilities

• Design, develop, test, and deploy scalable, high-quality experiences — whether that's front-end work in React, Next.js, and modern TypeScript, or backend work in Go (modeling data for markets, orders, and transactions) — while making meaningful contributions on the other side of the stack too
• Contribute to the technical evolution of our Markets platform, partnering with product and design to deliver engaging, performant, and accessible features
• Implement and support features end-to-end: implementation → instrumentation → deployment → monitoring → iteration based on metrics
• Implement and maintain experimentation capabilities (feature flags, A/B tests) to validate ideas quickly and safely
• Integrate with backend APIs and collaborate with platform teams to build reliable, observable systems
• Participate in code reviews, focusing on code quality, readability, and maintainability
• Leverage AI tools to accelerate development velocity while maintaining high standards for security, correctness, and performance
• Follow and help improve team standards for AI usage (prompt patterns, code review checklists, validation strategies)
• Contribute effectively to an early-stage product environment, seeking opportunities to unblock others and take initiative

Qualifications

• 4+ years experience building highly scalable, production systems — whether that's user-facing web applications in modern JavaScript/TypeScript and React, or backend services in a language like Go, Java or Python. If you're frontend-strong, you don't need to arrive fluent in Go — just curious about what's happening beneath the UI
• Proficiency in React, component-driven development, and state management patterns, with familiarity with libraries like NextJS, TanStack Query, Tailwind, Zustand — or, on the backend, familiarity with data modeling and event-driven architecture (e.g. Postgres, Kafka/PubSub)
• Solid understanding of your primary language's features, idioms, and best practices (JavaScript/TypeScript or a backend language)
• Understanding of performance and reliability — responsive design, accessibility, and web standards on the front end; scalability, observability, and correctness on the backend
• Experience integrating with backend APIs and collaborating with cross-functional platform/infra teams
• Familiarity with CI/CD pipelines, testing strategies, and safe deployment practices for web applications
• Team-first mentality, with a willingness to do what it takes to get the job done and a desire to strive for better
• Experience using AI tools (Claude Code, Codex, Copilot, etc.) to ship production code
• Able to discuss how AI tools improve development workflow (e.g., boilerplate generation, debugging)
• Communicates technical concepts clearly to diverse audiences, including engineers and stakeholders
• Thrives in a fast-paced environment where priorities evolve regularly and decisions are made quickly
• Ability to collaborate cross-functionally across diverse teams

You don't need to tick every box — strength in one area and a willingness to learn goes a long way.

Preferred Qualifications

• Previous experience in early-stage or high-growth startup environments
• Contributions to open-source projects or technical communities
• Experience with real-money transaction systems and regulatory compliance
• Background in improving engineering productivity
• Interest in learning and influencing technical direction
• BSc in Computer Science or related field

Depending on the role, your interview and onboarding experience may include in-person components, such as onsite interviews or Launching into Better: LIVE—a multi-day cultural immersion in New York City for full-time, non-seasonal hires. These sessions are designed to build connection and bring our culture to life, though specific travel and participation requirements will be confirmed based on your role and location. Your recruiter will provide clear guidance at each stage of the process.

Ready to build the future of sports trading? If you possess some of these skills but not all of them, we still encourage you to apply! Please note that visa sponsorship is not available for this position. We are open to fully remote candidates based in the United Kingdom. Remote employees may also be eligible for a home office setup stipend.