Senior Software Engineer – Backend

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 Senior Software Engineer (Backend) role is a senior-level IC with significant ownership over the core trading platform underpinning all FMX operations. You will join a greenfield team building new services in Go, working alongside engineers with deep backgrounds in regulated financial infrastructure.

You will lead by example, establishing best practices for AI-assisted development while building systems that must meet the reliability, latency, and auditability standards of a regulated product.

We’re pioneering the use of AI as a code collaborator. We need engineers who have gone beyond experimentation and who actively use Claude Code, Cursor, Codex, GitHub Copilot, or similar tools to ship production code faster while maintaining exceptional quality standards.

Responsibilities:

• Lead the design, development, testing, and deployment of high-performance, fault-tolerant backend services supporting the FMX trading platform.
• Own services and features end-to-end: spec writing → implementation → instrumentation → deployment → monitoring → iteration based on metrics.
• Work within and help modernise a Java codebase while contributing to new service development in Go, Java and Kotlin.
• Contribute to the architecture for order processing, market data distribution, and trade lifecycle management on a regulated product.
• Build and maintain reliable daily reporting pipelines, ensuring data integrity and full audit trails across all trading activity.
• Participate in 24/7 on-call rotations; contribute to SLO definition, alerting strategy, and incident response for mission-critical trading infrastructure.
• Model and manage data for contracts, orders, positions, and settlements with an emphasis on correctness, integrity, and regulatory auditability.
• Collaborate with the DevOps/Platform team to ensure services are observable, scalable, and compliant with MNPI and insider trading restrictions.
• Conduct thorough code reviews, raising the bar on code quality, readability, security, and maintainability.
• Leverage AI tools to accelerate development velocity while maintaining high standards for security, correctness, and regulatory compliance.
• Establish and document team standards for AI usage (prompt patterns, code review checklists, validation strategies).
• Contribute to a fast-paced 0→1 environment, unblocking others and taking initiative where processes are still being defined.

Qualifications:

• 4+ years of experience building highly scalable, high-performance backend applications or distributed systems.
• Background in regulated exchange or financial infrastructure strongly preferred – brokerage, futures/derivatives exchanges (CBOE, CME, ICE), or similar CFTC/SEC-regulated environments. 
• Production experience with Java; Go experience or a strong demonstrated desire to work in Go.
• Experience with event-driven architectures (Kafka, Kinesis, PubSub, or similar) in a financial or high-throughput context.
• Strong understanding of data integrity and transaction management in PostgreSQL or equivalent RDBMS, including financial-grade data modelling.
• Solid grasp of software design principles (SOLID, DRY) and testing methodologies (unit, integration, end-to-end).
• Familiarity with CFTC compliance requirements, MNPI handling, and audit trail obligations in a regulated trading environment.
• Experience with CI/CD pipelines, automated testing, and safe deployment practices for backend services.
• Production reliability experience: monitoring, logging, alerting, on-call, and SLO 
• definition.
• Demonstrated experience using AI tools (Claude Code, Cursor, Copilot, etc.) to ship production code; able to articulate specific workflow improvements.
• Communicates complex technical concepts clearly to engineering, compliance, and business stakeholders.
• Thrives in a fast-paced, high-growth environment where priorities evolve and decisions are made quickly.

Preferred Qualifications:

• Previous experience at a US-regulated financial exchange or licensed trading platform (e.g. CBOE, CME, or similar).
• Familiarity with low-latency trading systems, order book design, or market data infrastructure.
• Previous experience in a 0→1 or high-growth startup environment.
• Contributions to open-source projects or the technical community.
• Experience leading without authority and influencing technical direction across teams.

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 connections 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 regulated prediction markets? 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.