Senior Software Engineer - Market Making in London

Our roster has an opening with your name on it. We are growing our Market Making Engineering team that works on some of the coolest software in the industry - 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 you will join works 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 collaboratively with a team to implement creative, high-quality solutions, scope effort and timelines, and balance priorities of our stakeholders and engineering needs. This team will work closely to deliver exceptionally high-quality software, while taking pride and ownership in testing, deploying, monitoring, and maintaining that software. 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 be 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 realised margin). You will go beyond the software developer role, and will be called upon to identify opportunities yourself in the quantitative space to innovate through technology.

THE GAME PLAN

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 and when it is not. Your solutions are pragmatic.

You consider the legacy of the code you produce and write code that an SDE unfamiliar with the system can understand. You limit the use of short-term workarounds. You do things with the proper level of complexity the first time (or at least minimise incidental complexity). You create flexible software without over-engineering. You make appropriate trade-offs, re-use where possible, and are judicious about introducing dependencies. You are efficient with resource usage (e.g., system hardware, database, memory/CPU, etc).

We are looking for engineers to actively engage in technical discussions, assist in designing and implementing solutions, pair program with our more junior engineers, and deliver constant improvements to our systems. We want you to be excited about constantly learning and driving your professional development.

You should have most, or all, of the following skills:

• Experience in both quantitative modelling practices and coding.
• You work in project ideas with stakeholders and peers.
• 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 the team requirements.
• You help your team evolve by actively participating in the code review process, design discussions, team planning, and ticket/metric/COE reviews.
• You classify, store, and handle data in accordance with FanDuel policies.
• You track security risks and mitigate and/or escape them in a timely manner.
• You focus on operational excellence, constructively identifying problems and proposing solutions.
• You take on projects and make software enhancements that improve the team software and processes.
• You work to resolve the root cause of complex problems, leaving software better and easier to maintain than when you found it.
• You are able to train new team-mates 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 a constructive dialogue and seek resolutions in a professional way.
• You help recruit and interview for your team.
• You estimate stories/tasks accurately and deliver them in time.
• You mentor and help to develop others.
• On-call rotation where required. You provide excellent customer support.
• You keep yourself up to date with market standards, 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 realised margin, exposure/capital utilisation).

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

THE STATS

What we are 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 awesome new feature ships to users and the positive feedback starts rolling in, you can feel really proud of what you and your team created.
• Personal development - clear and defined career pathways for every role at every level, a supportive manager, loads of learning opportunities and even 10% of your time to dedicate to your learning.
• Belonging - everyone at FanDuel works for each other, we win together, make mistakes together and have lots of fun doing it.
• Trust - A trusting work environment where productivity is valued above all else, 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 a number of other benefits.

ABOUT FANDUEL

FanDuel Group is the premier mobile gaming company in the United States and Canada. FanDuel Group consists of a portfolio of leading brands across mobile wagering including: America’s #1 Sportsbook, FanDuel Sportsbook; its leading iGaming platform, FanDuel Casino; the industry’s unquestioned leader in horse racing and advance-deposit wagering, FanDuel Racing; and its daily fantasy sports product.

In addition, FanDuel Group operates FanDuel TV, its broadly distributed linear cable television network and FanDuel TV+, its leading direct-to-consumer OTT platform. FanDuel Group has a presence across all 50 states, Canada, and Puerto Rico. The company is based in New York with US offices in Los Angeles, Atlanta, and Jersey City, as well as global offices in Canada and Scotland.

FanDuel Group is a subsidiary of Flutter Entertainment, the world’s largest sports betting and gaming operator with a portfolio of globally recognized brands and traded on the New York Stock Exchange (NYSE: FLUT).

Diversity, Equity and Inclusion

FanDuel is an equal opportunities employer. Diversity and inclusion in FanDuel 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.

FanDuel 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 Benefits@fanduel.com.

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!