Full Stack Developer

Fnality is building the future of financial market infrastructure – creating regulated, blockchain-based payment systems to power tomorrow’s wholesale banking ecosystem. Backed by leading global banks and operating at the intersection of technology, finance, and regulation, we are powering the future of finance, together.

There are no precedents for what we're doing. With you on our side, we'll be setting new ones every day. Working at Fnality Be your best: We have a supportive culture that helps to bring the best out of each and every single one of our employees. Feel free to explore: Bring your new ideas and help us to solve problems together by joining a community of experts.

Be part of something bigger: We will support you by fostering an open, honest culture, that enables flexibility and wellbeing. Feel part of something bigger while being yourself. Feel empowered: We want you to feel empowered. The nature of our business can help make this a reality. We have the agility, speed and innovation of a start-up, and a flexible working environment that enables this.

Role Overview We are looking for an experienced Full-Stack Software Engineer to join Fnality's Engineering team and help design, build and evolve the technology that supports the next generation of wholesale financial market infrastructure. You will work across the technology stack, developing secure and resilient backend services, APIs, integrations and user-facing applications.

You will contribute throughout the software development lifecycle, from technical design and development through testing, deployment and production support. This is a hands-on engineering role operating in a complex and highly regulated environment. You will work closely with engineers, product managers, platform teams, architects and other stakeholders to translate business and technical requirements into high-quality software.

You will also be expected to be AI fluent, using modern AI-enabled development tools appropriately to improve engineering productivity, software quality and problem solving while maintaining accountability for the security, integrity and quality of the software you produce.

Key Responsibilities

• Full-Stack Software Development using Python and React as main stack
• Design, develop, test and maintain applications across the full technology stack
• Build scalable and resilient backend services, microservices and APIs
• Develop intuitive and reliable web applications and user interfaces
• Translate product and business requirements into well-designed technical solutions
• Write clean, maintainable, secure and well-tested code
• Participate in code reviews, technical design discussions and architecture decisions
• Develop reusable components and engineering patterns that improve consistency and efficiency across the platform. Systems and Integration
• Build and maintain integrations between Fnality platforms, participant systems and external services
• Develop APIs and services that allow applications and platforms to interact securely and reliably
• Work with distributed systems and asynchronous or event-driven architectures
• Contribute to the integration of traditional financial technology with emerging digital asset and DLT-based infrastructure
• Troubleshoot complex issues across application, integration and platform layers. Engineering Quality and Security
• Build security, resilience, performance and maintainability into solutions from the outset
• Develop automated unit, integration and end-to-end tests
• Contribute to CI/CD and automated software delivery practices
• Apply secure software development and Dev. Sec. Ops principles
• Ensure applications meet appropriate engineering, security and operational standards
• Support observability through effective logging, monitoring and alerting
• Contribute to production support, incident investigation and root-cause analysis where required. AI-Enabled Engineering
• Use AI-assisted development tools effectively and responsibly to support coding, testing, documentation, troubleshooting and software design
• Apply strong engineering judgement when reviewing and validating AI-generated code or recommendations
• Identify opportunities where AI can simplify engineering workflows or improve internal applications
• Experiment with emerging AI technologies where they provide demonstrable business or engineering value
• Remain accountable for code quality, security and engineering decisions regardless of whether AI tools have been used in development. Collaboration and Continuous Improvement
• Work closely with Product, Architecture, Platform Engineering, DevOps, Security and other Engineering teams
• Participate in Agile ceremonies, technical planning and estimation
• Help define engineering standards and contribute to continuous improvement across the software development lifecycle
• Share knowledge and technical expertise with colleagues
• Stay current with developments across software engineering, cloud technologies, AI and distributed systems. Required Experience and Skills
• Experience developing backend applications and APIs using technologies such as Python (preferred), Java, Kotlin, C#, Node.js or similar
• Experience with modern frontend technologies such as React (preferred), TypeScript and JavaScript
• Strong professional experience as a software engineer working across both backend and frontend technologies
• Strong knowledge of object-oriented and/or functional software development
• Experience designing and consuming REST APIs and working with service-based architectures
• Strong understanding of software engineering principles, design patterns and clean-code practices
• Experience with relational and/or NoSQL databases
• Experience developing and deploying applications within a cloud environment such as Microsoft Azure, AWS or GCP
• Experience with automated testing and CI/CD
• Understanding of containerisation technologies such as Docker and Kubernetes
• Experience working with Git and modern collaborative software development practices
• Strong analytical and problem-solving skills
• Ability to communicate technical concepts clearly to both technical and non-technical stakeholders. Desirable Experience
• Experience within financial services, payments, banking, fintech or financial market infrastructure
• Knowledge of payment systems, settlement or transaction processing
• Experience building systems requiring high levels of resilience, availability and security
• Experience with event-driven architectures and technologies such as Kafka or similar messaging platforms
• Understanding of distributed systems and distributed ledger technology
• Exposure to Ethereum or enterprise blockchain technologies
• Experience working within a regulated technology environment
• Understanding of cybersecurity and secure development principles
• Experience integrating complex enterprise or banking systems
• Practical experience using AI-assisted software engineering tools such as GitHub Copilot or equivalent. What We Mean by AI Fluent At Fnality, AI fluency does not mean that this is an AI engineering role. We expect our software engineers to understand how modern AI tools can enhance the way software is designed, built and maintained.
• Use AI-assisted engineering tools effectively in day-to-day development
• Understand where AI can accelerate development and where traditional engineering approaches remain more appropriate
• Critically review and validate AI-generated code
• Understand the security, privacy and intellectual property considerations associated with AI-assisted development
• Explore practical opportunities to introduce AI capabilities into applications and engineering workflows
• Use AI to improve productivity without compromising engineering standards, security or accountability. What Success Looks Like
• Deliver high-quality features and applications across the full technology stack
• Develop secure and resilient solutions suitable for regulated financial infrastructure
• Improve the quality, maintainability and scalability of Fnality's software platforms
• Build effective integrations across Fnality's technology ecosystem
• Contribute to reliable and efficient software delivery
• Use AI-enabled engineering tools intelligently without compromising security, control or software quality
• Build a strong understanding of how technology supports Fnality's payment systems and the wider digital financial market ecosystem. Why should you join Fnality? We employ curious individuals who thrive working in a fast-paced and constantly changing environment, who work best when empowered to drive their own work, and who are not afraid to fail fast and learn quicker. You will join a team working on the next iteration of the payment system at a time when Fnality is onboarding with major currencies. The work involves evolving the core payment infrastructure, a critical part of Fnality’s product offering. You will be part of a growing in-house capability, joining early enough to shape how it's built. A bit more about us Digital transformation is changing our lives, work and businesses. While other sectors evolve, however, financial markets remain slow, fragmented and siloed. What the world needs now is a future-facing financial system for the digital age. At Fnality, we have been speaking – and listening – to the real users of today’s financial systems. From businesses to banks, there is a clear, collective ambition for a simpler, faster, safer and more resilient payment system; one that can move and settle money quickly and efficiently, with minimized risk and much more transparency. Fnality Global Payments We are building a network of new payment systems that will enable tokenised, peer-to-peer markets. Fnality Global Payments (FnGP) will comprise a series of national systems, each regulated in its home jurisdiction. We call each of these a Fnality Payment System (FnPS). In each payment system, a Fnality settlement asset will act as the settlement/payment asset for any Payment (P), Delivery vs. Payment (DvP) or Payment vs. Payment (PvP) need. FnGP are underpinned by Distributed Ledger Technology (DLT). The nature of DLT is such that it enables FnGP to:
• Operate a true peer-to-peer market
• Allow for immediate settlement
• Interoperate across business platforms and jurisdictions The key benefits of the above are:
• Reduced counter-party and credit risk
• Reduced operational risk
• Efficient liquidity management
• An ability to move resources from risk mitigation to business growth Eligibility This is a London based role and you must be eligible to work in the UK. Please note we cannot sponsor visas for this role. How will we use the information about you? We will use your personal information to process your application, to enable us to assess your suitability for a role and for other legitimate business purposes such as improving our sites and talent management practices. We may share your data with third parties to achieve these purposes. We will not use or share your information for marketing purposes. We will take appropriate security measures to safeguard your information in accordance with data protection legislation. If you would like further information about how your information may be processed by us, please contact us at privacy@fnality.org.