What You Won’t Have to Do in this role
- Be bogged down by red tape or excessive bureaucracy.
- Check in repeatedly or wait for permission to try new ideas.
- Aim for perfect code or endless code reviews.
Are you a creative problem-solver who thrives in a fast-paced, experimental environment? Do you relish the challenge of building prototype software quickly, testing ideas, and learning from failure as much as success? Mustard Systems is seeking a Senior Software Developer to join our talented Horse Racing trading team, where you'll collaborate with a unique blend of mathematicians, statisticians, international chess masters, and Countdown Octo-Champs to tackle some of the most complex and exciting problems in sports prediction.
The Horse Racing team specialises in predicting the outcomes of Horse Racing around the world with the primary focus of the team being building in-house sophisticated trading systems and predictive models.
In this role, you’ll work alongside some of the sharpest minds in the industry, in a culture that values creativity, experimentation, and diversity of thought. If you’re ready to make an impact by innovating at the cutting edge of sports prediction, we’d love to hear from you.
This isn’t a role for a by-the-book developer. Instead, it’s perfect for someone who enjoys exploring uncharted territory, using their technical expertise to experiment, innovate, and deliver rapid results. You’ll act as a senior member of the team, bringing your own creative ideas and experience to drive projects forward while mentoring others.
What You’ll Do
- Build new prototype software from the ground up, focusing on speed of execution over polished perfection.
- Have freedom to build software the way you want with minimal restrictions to following the status quo.
- Lead experiments to test innovative approaches and iterate quickly, embracing failure as part of the process.
- Collaborate closely with a team of experts across disciplines to bring diverse perspectives to problem-solving.
- Use your technical skills and creativity to identify the best tools and technologies for the task at hand.
- Work predominantly in-office, fostering close collaboration and a team-driven approach.
- Act as a senior developer, bringing leadership, mentorship, and fresh ideas to the team.
Requirements
We want someone who will bring something new to our team, complementing our existing mix of expertise with a fresh perspective. To succeed in this role, you’ll need:
- At least 5 years of software development experience, with a proven ability to work independently and innovate.
- A passion for creative problem-solving and a willingness to fail fast to find the best solution.
- Experience working in environments where the speed of development is prioritised over formal processes.
- An eagerness to collaborate with a diverse team of brilliant minds, contributing your own unique insights.
- A self-starter attitude, with the confidence to take ownership of projects and experiment with new ideas.
- A firm understanding of how to get the most out of AI to assist your work and a keenness to stay up to date with the latest AI developments. (This isn’t just buzzwords - we really do believe in this!)
- A willingness to work mostly in the office, recognising the value of face-to-face teamwork for this role.
Our Tech Stack
You’ll have the freedom to choose the tools and technologies that fit each problem best, but here’s a snapshot of what we currently use:
- Python 3.10+ for most of our development.
- C and Go for high-performance systems where needed.
- Linux servers.
- PostgreSQL for data storage.
- RabbitMQ and Kafka for backend communication.
- Basic web front ends for internal tools.
Your Portfolio or Personal Projects – we’re especially keen to see what you’ve built outside of your day job. Whether it’s a passion project, an experimental tool, or something a little quirky, we’d love to hear about it. These projects often tell us more about your creativity and approach to problem-solving than a standard CV ever could.
Benefits
Comprehensive benefits, including:
- Competitive salary and significant bonus potential (based on company and personal performance)
- Enhanced pension match with salary sacrifice option.
- Health insurance and life assurance.
- Sabbatical leave after five years.
- 33 days of annual leave (including bank holidays).
We have a hybrid working approach at Mustard Systems. We enjoy working and collaborating together and require people to be in our Hammersmith office four days a week. If you require any additional flexibility, please let our hiring team know as part of the recruitment process.
Top Skills
Mustard Systems London, England Office
Colet Court, 100 Hammersmith Road, London, United Kingdom, W6 7JP


