Staff Engineer - Core Markets

Staff Engineer - Core Markets LocationLondonEmployment TypeFull timeDepartmentEngineeringAbout 9fin9fin is the AI platform powering global debt markets — the world’s largest asset class at over $145 trillion.Debt markets are vast, global, and mission-critical, yet still run on fragmented data, PDFs, and manual workflows. 9fin replaces this broken infrastructure with a single platform that centralises proprietary credit data, deep analysis, and high-value workflows across global markets.Today, 9fin powers teams at 300+ blue-chip institutions worldwide, including global banks, asset managers, private equity firms, law firms, and advisors. The business is scaling at exceptional speed, with rapid expansion in the US and best-in-class retention driven by deep workflow adoption.We’re at a defining inflection point. With proven product-market fit and strong, global market pull, 9fin is accelerating toward becoming the category-defining platform for debt markets worldwide.We’re looking for a Staff Engineer to lead the technical vision and architecture for 9fin’s Core Markets engineering organisation. In this role, you’ll define and evolve the system design that underpins our future expansion—owning the end-to-end architecture, setting technical direction, and ensuring our platforms scale effectively. You’ll create clear technical documentation, align multiple engineering teams around a shared vision, and guide execution by helping teams make thoughtful trade-offs. This is a high-impact, hands-on leadership role on the IC track. You’ll operate across strategy and execution—partnering with 6+ teams, contributing directly to critical code paths when needed, and raising the engineering bar across the organisation. What you'll doDefine technical strategy and architecture across Platform, AI, Retrieval, and shared engineering services.Partner with Engineering Leaders and Staff Engineers to drive technical direction and platform investments.Design scalable backend systems, APIs, and shared platform capabilities.Guide architecture across teams, helping reduce complexity and establish common patterns.Partner with AI and Retrieval teams to build scalable search and RAG capabilities.Lead complex cross-team technical initiatives from design through production.Improve platform reliability, scalability, observability, and developer experience.Contribute hands-on to critical technical work and set a high engineering bar through design reviews, mentoring, and technical leadership.Leverage AI-assisted engineering to improve productivity and accelerate delivery.  What we're looking forExperience designing and building large-scale backend systems and distributed architectures.Strong systems design skills and experience leading cross-team technical initiatives.Experience with cloud infrastructure (AWS), Kubernetes, APIs, and modern backend development.Familiarity with AI-powered systems, Retrieval-Augmented Generation (RAG), search platforms, or vector databases.Strong programming experience in Python or another modern backend language.Comfortable influencing technical direction without direct authority.Excellent communication skills and a passion for mentoring engineers and raising engineering standards.  Nice to have:Experience as a founding engineer or CTO at a startup, or building systems from scratch in early-stage environmentsExperience modernising legacy systems.BenefitsWe’re a scaling start up and we enjoy sharing our success, when the company succeeds, we always reinvest that in our people. We also offer huge amounts of responsibility, an abundance of opportunity for growth and a platform to truly excel.Financial & InsuranceCompetitive Salary (our salary bands are benchmarked at the top end of the market)Equity optionsPension (your minimum contributions are 4% with 9fin matching up to 7%)Private Medical InsurancePaid sick leave with Income Protection for long periods of illnessGroup Life AssuranceSeason Ticket Loan & Cycle to Work schemesTime...