Software Engineer (backend) in Cardiff

Location: UK (Remote)

Salary: £125k –£145k + annual performance bonus

No visa sponsorship offered

Capital markets move trillions. The legal documents underpinning those transactions are dense, nuanced, and mission-critical, and right now, most of that complexity is still handled by hand. This company is changing that.

Built on years of machine learning PhD expertise, backed by a top-tier venture firm, and now operating at global scale following a high-profile acquisition, this team is tackling some of the hardest NLP problems in finance and law. Their customers include many of the world's leading law firms and the demand for what they're building is accelerating fast.

As a Software Engineer, you won't be maintaining someone else's roadmap. You'll be architecting the critical backbone between a cutting-edge AI data platform and the professionals who depend on it daily. Your decisions will ship. Your influence will stick.

If you want to do the most meaningful work of your career, in a team that moves fast, thinks deeply, and gives a damn about craft - read on.

The Role

• Design and build scalable backend services and APIs that power a document analysis platform used by major legal and financial institutions
• Write high-performance, maintainable server-side code and data processing pipelines
• Define clear, efficient API contracts and contribute meaningfully to service architecture decisions
• Design compositional API primitives that accelerate the productionisation of a growing library of document insights
• Build and maintain integrations with third-party services and internal ML systems
• Contribute to frontend features and components as needed to deliver end-to-end functionality
• Drive performance optimisation for data-intensive backend operations
• Champion engineering excellence — contribute to code practices, design patterns, and long-term maintainability
• Improve developer experience by automating and improving CI/CD and day-to-day production operations

Skills Needed

Required:

• 6+ years of professional full-stack development experience with a strong backend focus
• Proficiency in backend technologies - Python (FastAPI, Django, or Flask) is preferred; Node.js, Java, or Go also considered
• Strong understanding of RESTful APIs, database design, and data modelling (SQL and NoSQL)
• Experience with containerisation and orchestration (Docker, Kubernetes) and cloud platforms (AWS preferred)
• Proficiency in TypeScript and React for frontend contributions
• Foundation in distributed systems, event-driven architectures, and web fundamentals
• Strong communication skills and a self-starting, action-biased approach to problem-solving
• Bachelor's degree in Computer Science or related field, or equivalent practical experience

Preferred:

• Experience with microservices architecture and message queues
• Experience building data processing pipelines or working with large-scale data systems
• Familiarity with CI/CD best practices and single-tenant architectures
• Experience optimising backend performance for data-intensive applications
• Mentorship experience and a track record of ownership in previous roles
• Interest in language, economics, or legal/financial domains

Benefits

• 15 - 20% annual performance bonus
• Fully remote - work from anywhere in the UK
• Private medical, dental, and vision insurance
• Pension and retirement planning support
• Health and wellbeing reimbursement (including fitness and mindfulness)
• Flexible paid time off

Research indicates that men will apply to a role when they only meet 50-60% of the descriptions, however, when looking at women and other minority groups, they can look for up to a 99% match in order to apply to a role. If you feel you are a fit for our role, please still apply, don’t worry if you don’t tick every single box. We’d still love to hear from you. We encourage underrepresented talent to apply to all our roles & support accessibility needs.