Senior Software Engineer – Market Making - FanDuel Careers in London

We’re growing our Market Making Engineering team that works on the systems that quote, price, and manage risk in real time for high-volume, high-velocity sports markets. This work spans the full RFQ/quote lifecycle (request → quote → accept → outcome) in low-latency, event-driven services. The team collaborates with quantitative analysts and trading/risk stakeholders to implement and run market making strategies, while proactively identifying opportunities for technical innovation within the Risk and Trading organization.

As a Senior Software Engineer within FanDuel’s Market Making Technology team, you will be an essential part of a cross functional agile team that directly impacts our business. You will work to implement creative, high-quality solutions, scope effort and timelines, and balance priorities of stakeholders and engineering needs. The team will deliver high-quality software with ownership of testing, deployment, monitoring, and maintenance. Our engineers own every part of the software delivery lifecycle.

You will work directly with quantitative analysts at FanDuel to improve our market making capabilities. You will become a domain expert on strategy implementation (quoting/decision logic) and how that fits into the larger Risk and Trading landscape — including real-time risk controls, execution outcomes, and performance measurement. You will help ensure robust guardrails (limits, throttles, kill switch) and high-fidelity decision logging so strategies can be debugged, replayed, and improved (e.g., quote ratio, win rate, expected vs realized margin). You will go beyond the software developer role and identify opportunities in the quantitative space to innovate through technology.

THE GAME PLAN

Everyone on our team has a part to play. You are a significant and autonomous contributor. Your work is consistently of high quality. You solve difficult problems, applying appropriate technologies and best practices. You work with your team to invent, design and build software that is stable and performant. You are proficient in a broad range of design approaches and know when it is appropriate to use them. Your solutions are pragmatic and considerate of the legacy of the code you produce. You write code that others can understand, avoid short-term workarounds, and balance complexity. You create flexible software without over-engineering, make appropriate trade-offs, re-use where possible, and judiciously introduce dependencies. You are efficient with resource usage (e.g., system hardware, database, memory/CPU).

We are looking for engineers to actively engage in technical discussions, assist in designing and implementing solutions, pair program with junior engineers, and deliver constant improvements to our systems. We want you to stay excited about learning and developing professionally. You should have most, or all, of the following skills:

• Experience in both quantitative modeling practices and coding.
• You own parts of product and technology & become subject matter experts.
• You write simple and extendable code following standards and best practices.
• You test your code thoroughly.
• You help balance customer requirements with team requirements.
• You help your team evolve by actively participating in code reviews, design discussions, planning, and ticket/metric/COE reviews.
• You classify, store, and handle data in accordance with FanDuel policies.
• You track security risks and mitigate or escalate them in a timely manner.
• You focus on operational excellence, identify problems, and propose solutions.
• You take on projects and make software enhancements that improve team software and processes.
• You work to resolve root causes of complex problems, leaving software better and easier to maintain.
• You can train new teammates on how your team’s software is constructed, how it operates, how secure it is, and how it fits into the bigger picture.
• You foster constructive dialogue and seek resolutions professionally.
• You help recruit and interview for your team.
• You estimate stories/tasks accurately and deliver them on time.
• You mentor and help develop others.
• On-call rotation where required.
• You provide excellent customer support.
• You keep up to date with market standards and open-source frameworks.
• You build and evolve components that support real-time quoting and decisioning with careful attention to latency, throughput, and correctness.
• You implement and maintain risk controls and guardrails (e.g., exposure checks, limits, throttling/filters, kill switch patterns).
• You ensure high-quality decision logging so strategies can be debugged, replayed, and improved using real quote/fill outcomes.
• You partner with quants and stakeholders to define and monitor key metrics (e.g., quote ratio, win rate, expected vs realized margin, exposure/capital utilization).

Most importantly, you are humble, pragmatic, self-managed, thirsty for knowledge, never satisfied and always challenging the norm. You are responsible for the state of the code you inherit and produce. Creative problem-solving ability. A passion for learning and always getting better.

THE STATS

What we’re looking for in our next teammate:

• Degree in Computer Science, Data Science, Engineering, Mathematics, Physics, or related discipline.
• 5 or more years of industry experience in an Engineering field, Machine Learning, Data Science, Finance Engineering, or Statistics.
• 5 or more years of software development experience.
• Proficient in building services with a modern OOP language (C# experience is beneficial).
• Understanding of performance, hardware, and lower level memory management (C, C++, or Rust experience is beneficial).
• A fundamental understanding of data structures and algorithms.
• Proficient in working with GitOps Patterns.
• Experience working with CI/CD pipeline tooling (BuildKite and GitHub Actions knowledge is beneficial).
• Experience working with cloud-based infrastructure and technologies.
• Knowledge of AWS with API gateway/workflow orchestration/lambda/serverless applications.
• Knowledge of infrastructure as code is nice to have, notably Terraform and Helm.
• Experience interacting and designing relational databases.
• Experience with streaming technologies (Kafka is nice to have).
• Ability to document code, research, and designs clearly (Jira and Confluence experience nice to have).
• Proficiency in translating requirements into design and developing applications.
• Understanding of containers (e.g. Docker), and orchestration (Kubernetes).
• Demonstrated abilities driving operational excellence and on call support.
• Experience with unit testing, testing tools, integrating testing and best-quality practices into an SDLC.
• Experience working in an Agile environment.

Nice to have (Market Making):

• Experience building event-driven / real-time systems where observability (logs/metrics/traces) and safe rollout patterns are critical.
• Familiarity with concepts like exposure, hedging, inventory/position, and performance measurement in decision systems.
• Experience with backtesting/simulation, replay tooling, or strategy evaluation workflows.

What You Can Expect

• Interesting work - working in a fast-paced and ever-changing industry, new problems and exciting solutions are never too far away.
• A sense of achievement - Our teams own their own software and when that feature ships to users, you can feel proud of the impact.
• Personal development - clear and defined career pathways for every role at every level, supportive management, ample learning opportunities, and even 10% of your time dedicated to learning.
• Belonging - everyone at FanDuel works for each other, we win together, make mistakes together, and have fun doing it.
• Trust - A trusting work environment where productivity is valued, giving you autonomy and ownership of your time and work.
• Great financial package - Including salary, bonus, pension, private healthcare, share save scheme, flexible working & holiday policy, along with other benefits.

ABOUT FANDUEL

FanDuel Group is the premier mobile gaming company in the United States and Canada, with leading brands across mobile wagering including FanDuel Sportsbook, FanDuel Casino, FanDuel Racing, and its daily fantasy sports product, plus FanDuel TV and FanDuel TV+. The company operates across multiple regions and offices including New York, Los Angeles, Atlanta, Jersey City, Canada, Scotland, Ireland, Portugal, Romania, and Australia. FanDuel Group is a subsidiary of Flutter Entertainment, traded on the NYSE (FLUT).

Diversity, Equity and Inclusion

FanDuel is an equal opportunities employer. Diversity and inclusion are valued, and bias, judgement or harassment are not tolerated. We focus on developing employees so they reach their full potential.

FanDuel is committed to providing reasonable accommodations for qualified individuals with disabilities. If you need a workplace accommodation during the application and hiring process, please reach out.

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!