Staff Full Stack Engineer - Sell Side Engine

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Staff Full Stack Engineer - Sell Side Engine based in United Kingdom. This is a highly hands-on Staff Engineer role focused on solving complex technical problems within a rapidly scaling energy technology environment. You will join a small, high-impact product squad responsible for rebuilding the systems that support renewable energy origination, contracting, onboarding, and growth. The role combines deep backend and systems engineering with the flexibility to contribute to frontend development when needed. You will make architecture-level decisions across integration-heavy systems, working with pricing, data, billing, and risk platforms. A major focus will be turning manual and error-prone commercial processes into scalable, automated products that can support new business categories. You will work with significant autonomy, operating within ambiguity and taking complex problems from definition through production delivery. This is an opportunity for an exceptional engineer to directly influence critical market infrastructure while helping build the technology behind a more transparent and efficient energy ecosystem. Accountabilities: - Own architecture-level decisions for complex, integration-heavy systems, clearly defining system boundaries, contracts, dependencies, and failure modes. - Design and build the technical foundations connecting new-product initiatives with pricing, settlement, data, billing, and other core platforms. - Take commercially driven and sometimes ambiguous problems, define practical technical approaches, and turn them into shippable plans within the squad's strategic direction. - Help develop and launch new product categories, contributing to the technical work required to bring new offerings from concept through production and qualified commercial pipeline. - Automate and productise tendering, pricing, contracting, onboarding, and other manual workflows that currently limit scalability and create operational risk.

- Design deal-gating and risk-management tooling that enables the business to safely support new categories of commercial risk. - Work effectively across organizational boundaries, delivering integrations and technical outcomes that depend on teams you do not directly manage. - Build high-quality software across backend services and, when appropriate, contribute to React and TypeScript frontend development. - Write clean, maintainable, and well-tested code, participate actively in code reviews, and contribute to stronger engineering practices and documentation. - Help measure and improve the reliability, scalability, and business impact of the systems you build. Requirements: - Deep technical expertise in backend engineering and systems design, with a proven track record of making architecture-level decisions for complex, integration-heavy systems. - Strong professional experience with Python and AWS serverless technologies, including Lambda, API Gateway, DynamoDB, and EventBridge. - Solid understanding of event-driven architectures and distributed systems. - Full Stack or Backend Engineering experience in a startup, scale-up, or fast-paced product environment, with ownership of complex projects from inception through delivery. - Ability to work effectively without a complete specification, turning an ambiguous problem into a practical, well-scoped, and shippable technical plan. - Demonstrated experience delivering projects where critical dependencies are owned by other teams, requiring strong collaboration and influence without direct authority. - Strong product mindset and ability to connect technical decisions to commercial outcomes and customer or business value. - Comfortable working hands-on across the stack, with React and TypeScript experience considered a plus rather than a core requirement.