Senior Software Engineer | Full Stack | Investment Tech | London, Hybrid

Senior Software Engineer | Full Stack | Investment Tech | London, Hybrid We’re hiring a Senior Software Engineer to join a London-based Investment Technology team building the platforms used for risk, analytics, and investment decision-making. This is a genuinely hands-on role: you’ll ship production features, improve reliability, and help shape modern engineering standards across a business-critical platform. If you enjoy solving real problems with clean, testable code (and you don’t need ten meetings to write a function), you’ll fit right in. 📍 London City | Hybrid (3 days in office) 💷 Competitive base + bonus + benefits ⏱️ Permanent Role 🚫 No sponsorship available What you’ll be doing • Build and evolve backend services in C#/.NET (performance, correctness, maintainability) • Develop data-driven APIs and pipelines (Python services, e.g., FastAPI, and integrations) • Deliver modern React UI components that are fast, usable, and predictable • Troubleshoot issues end-to-end across app + data layers (you’ll own problems, not just spot them) • Implement and improve CI/CD using Azure DevOps and/or GitHub Actions • Partner with business stakeholders to clarify requirements and iterate quickly • Keep documentation lightweight but useful (the goal is clarity, not a novel) What we’re looking for (must-haves): • Strong commercial experience with C#/.NET • Production experience with React (you’ve built real UIs, not just tweaked CSS) • Hands-on Python (FastAPI or similar is a plus) • Solid SQL skills (querying, performance awareness, data modelling basics) • Strong testing mindset: unit tests in C# and ideally Python too • Clear communicator who can work with technical and non-technical stakeholders • Exposure to investment management / fixed income domains Nice to have: • Azure experience (Functions, App Services, storage, monitoring) • Containers: Docker (and Kubernetes is a bonus) • Microservices patterns and practical trade-offs • CosmosDB / NoSQL, Snowflake, or similar data platforms • Front-end testing (e.g., Playwright/Jest) and UI libraries (e.g., Material UI) Why this role? • Modern stack (C# + React + Python + cloud) with genuine delivery ownership • Work directly on systems that influence investment decisions, not internal admin tooling • A team that values engineering quality (testing, code reviews, automation) 📧Interested? Apply directly with your CV to this advert or email it to chantelle.smith@sourcegroupinternational.com