Senior Software Engineer

Leads the design, development and delivery of high-scale applications as a full stack senior engineer. It owns frontend architecture for web and mobile products end to end while working across the stack to build and extend supporting services. The engineer will autonomously architect resilient systems, set technical direction, establish modern engineering standards, mentor other engineers and collaborate with cross-functional partners on technical and product initiatives.

• Autonomously drive sustained business impact across team goals, product capabilities and technical systems.
• Take ownership of semi-annual and annual technical objectives, delivering high-quality, mission-critical systems on schedule.
• Define and shape the long-term architectural vision for core full stack and microservices platforms.
• Architect technical solutions for complex, ambiguous engineering challenges, making sound trade-offs between immediate velocity and long-term system health.
• Lead cross-team technical initiatives to extend software standards and platform impact across engineering, and proactively manage technical dependencies and align architectural strategy across external engineering teams.
• Mentor engineers, influence organisational design standards and champion best engineering and operational practices.
• Partner with product and business stakeholders to resolve ambiguity, clarify requirements and address technical risks early in the lifecycle.
• Leverage deep domain knowledge to guide technology choices independently in fast-paced, high-scale environments, and streamline complex application architecture by focusing on core scalability, efficiency and critical business outcomes.
• Architect and build resilient, secure and maintainable applications under high traffic loads, and develop high-performance front-end interfaces and back-end microservices using modern frameworks and design patterns.
• Design, build and optimise high-throughput GraphQL APIs, and lead rigorous code reviews, testing strategies and engineering excellence across the software development lifecycle.

• Degree in Computer Science or a related field, or equivalent practical experience, with 5+ years building and shipping production software.
• Deep expertise in modern web frontend architecture with TypeScript, JavaScript (ES6+) and React, including component design, state management and hooks.
• Mobile development with React Native, plus readiness to work natively; the mobile apps are migrating to native Swift/iOS and Kotlin/Android with AI tooling, so the candidate is either comfortable in native mobile or a strong engineer eager to pick it up fast.
• Strong command of HTML5, CSS3, responsive design and cross-browser/cross-device compatibility across web and mobile.
• Proven track record of frontend performance optimisation: code splitting, lazy loading, bundle/asset optimisation, rendering performance and Core Web Vitals.
• Test-first mindset with hands-on frontend testing experience (e.g. Jest, React Testing Library) and a commitment to code quality, maintainability and observability.
• Working knowledge of backend services in Java and Spring Boot, enough to build and extend APIs and collaborate closely with backend teams.
• Experience consuming and integrating APIs on the client, including GraphQL.
• Solid grasp of software design patterns and architectural best practices for reliable, scalable and maintainable systems.
• Hands-on use of AI development tools (AI coding assistants, agentic IDEs, LLM-based testing or review tools) in real projects.
• Strong communication and cross-functional collaboration skills.
• Proven technical leadership: mentoring engineers, setting technical direction and raising engineering standards across a team.

• Experience with design systems, reusable component libraries and accessibility (WCAG) best practices.
• Familiarity with relational databases, messaging/streaming concepts (e.g. Kafka) and GraphQL federation (e.g. Cosmo).
• Experience with CI/CD pipelines and build tooling (e.g. Gradle, Buildkite).
• Cloud infrastructure (preferably AWS), containerisation (Docker) and orchestration (Kubernetes); exposure to Helm and Terraform is a plus.
• Existing Swift or Kotlin experience is a plus.

• Health plans to choose from, some as low as $0 per paycheck, including fertility and family planning programmes, mental health support and fitness benefits.
• Medical, vision and dental insurance; life insurance; disability insurance.
• Generous paid time off (PTO and sick leave), including paid personal time off and 14 paid company holidays, plus paid sick time in accordance with applicable state and federal laws.
• Annual bonus and long-term incentive opportunities based on performance, with possible eligibility for short-term or long-term incentive compensation including cash bonuses and stock programme participation.
• 401k with up to a 5% match.
• Commuter benefits.
• Pet insurance.
• Other benefits through FanDuel Total Rewards; benefits differ across location, role and level.

FanDuel Group is the premier mobile gaming company in the United States and Canada, with a portfolio of leading brands across mobile wagering including FanDuel Sportsbook, FanDuel Casino, FanDuel Racing and daily fantasy sports. FanDuel Group has a presence across all 50 states, Canada and Puerto Rico, is based in New York with US offices in Los Angeles, Atlanta and Jersey City and global offices in Canada and Scotland, and is a subsidiary of Flutter Entertainment, the world's largest sports betting and gaming operator traded on the New York Stock Exchange.