Senior Software Engineer - React​/React Native

THE POSITION

We're looking for a Senior Software Engineer to join our Sports book Core Apps engineering team. You'll be working on foundational engineering, focusing on improving the underlying frameworks, tooling, and performance that enable Fan Duel to deliver an exciting and innovative customer experience.

Working with our React Native Sports book application, you'll enhance the core React Native platform and shared codebase to improve performance, scalability, reliability, and developer experience. You'll collaborate closely with engineers across the org to ensure the React Native stack integrates cleanly with native layers and enables feature teams to deliver safely and quickly.

We're looking for skilled engineers who are empathetic communicators with a commitment to continuous improvement and engineering excellence. The ideal candidate has significant experience delivering production React Native applications, can propose pragmatic solutions to performance and platform challenges, and enjoys mentoring others and raising quality standards. As a member of this team, you will strengthen the foundations of our mobile platform, enabling Fan Duel engineers to deliver features more effectively while maintaining platform quality and best practices.

We are a growth company so there are plenty of opportunities for you to learn & grow with us.

• Enhancing the core React Native codebase for the Sports book app, focusing on performance, scalability, and maintainability
• Profiling and optimising app startup and runtime performance across the React Native stack (rendering, bundle size, memory, JS/native thread work, etc.)
• Building and maintaining shared frameworks, tooling, libraries, and components that support feature teams
• Improving developer experience through better tooling, documentation, templates, CI reliability, and build performance
• Contributing to technical design discussions and leading multi-phase improvements, breaking work into incremental, testable deliveries aligned with team priorities
• Supporting continuous improvement initiatives that raise quality, reduce toil, and improve operational readiness within the domain
• Joining our on-call rota, sharing out of hours support duties as part of our incident response process

• Significant experience delivering production React Native applications (OR strong React skills with interest in mobile development)
• Strong Type Script skills and a solid understanding of React patterns, architecture, and maintainable code practices at scale
• Practical experience profiling and improving performance in React Native applications (startup time, rendering, responsiveness, memory, etc.)
• Experience with React Native native modules / bridging; native Android (Kotlin/Java) and/or iOS (Swift) experience is a plus
• Familiarity with mobile development best practices, testing strategies, and CI/CD pipelines
• Experience working in Agile teams and contributing to collaborative technical standards
• A quality-focused mindset with strong problem-solving skills and the ability to evaluate trade-offs in ambiguous situations

• Contribute meaningfully to technical design discussions and propose pragmatic solutions aligned with our technical vision
• Take ownership of delivering platform improvements end to end, including measurement, rollout, and iteration
• Mentor and support other engineers, raising the bar through thoughtful reviews, coaching, and knowledge-sharing
• Participate in wider engineering community initiatives and help spread best practices

Fan Duel is an equal opportunities employer. Diversity and inclusion in Fan Duel means that we respect and value everyone as individuals. We don't tolerate bias, judgement or harassment. Our focus is on developing employees so that they reach their full potential.

Fan Duel is committed to providing reasonable accommodations for qualified individuals with disabilities. If you have a disability and need a workplace accommodation or adjustment during the application and hiring process, including support for the interview or onboarding process, please email

The requirements listed in our job descriptions are guidelines, not hard and fast rules. You don’t have to satisfy every requirement or meet every qualification listed. If your skills are transferable and you are in the ballpark experience-wise, we'd love to speak to you!