Senior Fullstack Engineer – Business Banking – Core Banking

At OakNorth, we're on a mission to empower ambitious businesses and the communities they serve. Since 2015, we've lent over $21 billion across the UK and US, helped create more than 58,000 new homes and 36,000 new jobs, and supported hundreds of thousands of personal savers — all while driving economic growth in the markets we serve. The Core Banking team owns the foundational systems that power our financial products and ensure the integrity of our data and processes. Own the financial accounts domain, including the design, creation, and lifecycle of financial products, ensuring they are compliant, scalable, and seamlessly integrated with the ledger and third-party systems. Manage our ledger (Thought Machine Vault Core), covering its integration, data integrity, and technical migrations, while maintaining a close partnership with the Thought Machine team. Build resilient, event-driven systems that ensure data consistency and traceability across internal platforms and external services. Support financial and regulatory reporting, including reconciliations and compliance obligations such as FSCS. Provide the systems and data models that ensure auditability, accuracy, and trust, from customer balances to external reports. About Us We’re OakNorth Bank, and we embolden entrepreneurs to realise their ambitions, understand their markets, and apply data intelligence to everyday decisions to scale successfully at pace. Banking should be barrier-free. It’s a belief at our very core, inspired by our entrepreneurial spirit, driven by the unmet financial needs of millions, and delivered by our data-driven tools. And for those who love helping businesses thrive? Our savings accounts help diversify the high street and create new jobs, all while earning savers some of the highest interest on the market. But we go beyond finance, to empower our people, encourage professional growth and create an environment where everyone can thrive. We strive to create an inclusive and diverse workplace where people can be themselves and succeed. Our story OakNorth Bank was built on the foundations of frustrations with old-school banking. In 2005, when our founders tried to get capital for their data analytics company, the computer said ‘no.’ Unfortunately, all major banks in the UK were using the same computer – and it was broken. Why was it so difficult for a profitable business with impressive cashflow, retained clients, and clear commercial success to get a loan? The industry was backward-looking and too focused on historic financials, rather than future potential. So, what if there was a bank, founded by entrepreneurs, for entrepreneurs? One that offered a dramatically better borrowing experience for businesses? No more what ifs, OakNorth Bank exists. For more information regarding our Privacy Policy and practices, please visit: https://oaknorth.co.uk/legal/privacy-notice/employees-and-visitors/ The role 👋 - Have a strong technical background, including 5+ years of experience designing and engineering large-scale systems. - Measure your success in terms of business impact, not lines of code. - Internalise the best ideas from across the organisation, humbly setting a vision that others can get behind. - Embrace DevOps culture: You build it, you run it. - Work well cross-functionally and earn trust from co-workers at all levels. - Care deeply about mentorship and growing your colleagues. - Prefer simple solutions and designs over complex ones. - Enjoy working with a diverse group of people with different areas of expertise. - You challenge the existing approach when you see the cliff edge racing towards us but also get on board once the options have been debated and the team has made a decision. - You're a broad thinker and have the capability to see the potential impact of decisions across the wider business. - Utilise GenerativeAI: Leverage GenAI tools to increase productivity and enhance decision-making processes within the role. It would be an added bonus if you have experience with/ knowledge of transaction monitoring, financial crime prevention, AML, and fraud detection. Nice to have: - Familiarity with transaction systems, statements, and reconciliation processes. - Experience using Thought Machine Vault Core. - Strongly preferred: Experience building and owning production Python systems. Technology 🧱 We're pragmatic about our technology choices. These are some of the things we use at the moment: - Python - PostgreSQL, BigQuery, MySQL - TypeScript, React, styled-components - Jest, React Testing Library, Cypress, pytest - AWS, GCP - ECS Fargate, Docker, Terraform, GitHub Actions How we expect you to work 👷‍♀️ We expect you to work in these ways, as well as encouraging and enabling these practices from others: - Collaborate 💬 - We work in cross-functional, mission-driven, autonomous squads that gel over time. We pair program to work better through shared experience and knowledge. - Focus on outcomes over outputs ✅ - Solving a problem for users that translates to business results is our goal. Measurements focused on that goal help us to understand if we are succeeding. - Practice continuous improvement 💡 - We optimise constantly.