> Markdown version of [/jobs/ext/1392867-principal-software-engineer-c](https://www.wearedevelopers.com/jobs/ext/1392867-principal-software-engineer-c). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Principal Software Engineer - C# - **Company:** TP ICAP - **Location:** London, UK - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** ASP.NET, .NET Framework, Application Programming Interfaces (APIs), Artificial Intelligence, Algorithmic Trading, Amazon Web Services, Software Applications, C Sharp (Programming Language), Cloud Computing, Code Review, Cyber Security, Relational Databases, Identity and Access Management, JSON, Message Broker, Windows Presentation Foundation, Node.Js, Software Architecture, Software Engineering, Software Requirements Analysis, TypeScript, WebSocket, Data Processing, ReactJS, Delivery Pipeline, Web Content, Information Technology, Api Design - **Published:** July 23, 2026 - **Apply:** https://uk.indeed.com/viewjob?jk=42f626ef1d823f9e ## About the Role * 10+ years Financial Services building complex front-office trading systems, with demonstrated technical leadership through multi-year delivery. * Demonstrated success leading engineering teams through complex, multi-year transformation programmes. * Hands-on experience across the full software development lifecycle. * Practical experience using AI tools across the development lifecycle, including the review discipline for AI-generated code. * Excellent written and verbal communication; effective in a matrixed, global organisation; self-motivated and proactive. * Degree in Computer Science, Engineering, Mathematics, Physics, or a relevant analytical discipline. Domain: * Understanding of relative-value execution: cash/futures basis, calendar spreads, curve trades, and how that translates into workflow and system requirements. * Familiarity with futures market structure (exchange, clearing, margining) and US Treasury market structure (cash bonds, primary dealers, settlement). * Knowledge of futures clearing/margin systems (e.g. CME) and Treasury settlement rails * Experience with execution/order connectivity protocols (FIX or equivalent) in an interdealer, agency, or execution-desk context. * Understanding of 24-hour, multi-region trading operations (follow-the-sun handover, timezone-aware processing across London/New York/Singapore) Technical: * Expert-level C# / .NET (LTS): back-end services with ASP.NET Core. * Experience designing and delivering event-driven, service-oriented back-end systems (message brokers, async workflows, API design) in a production trading environment. * Experience building desktop applications that host web content (e.g., Electron, Tauri, or custom .NET host); comfortable with WebSocket bridges, local service APIs, or IPC mechanisms to connect web UIs with native desktop applications. * Sufficient front-end literacy (React, TypeScript, Node) to make architectural decisions, review code, and collaborate effectively with dedicated front-end teams. * Demonstrated ability to leverage coding agents in spec-driven development workflows. * Strong grasp of process isolation, information security, and identity/access management; experience with event-driven messaging and least-privilege service boundaries. * Familiarity with modern build pipelines and tools. * Experience designing within formal governance and architecture-review frameworks. Desired * Experience with desktop interop frameworks and protocols (FDC3, OpenFin, or custom IPC/message-bus implementations). * WPF or other rich-client .NET UI experience. * Experience interfacing with third-party desktop APIs (e.g., Bloomberg DAPI). * Performance engineering: profiling and holding hard latency budgets. * Experience with high-throughput trade/market-data processing at scale. * Cloud platform experience (AWS or equivalent); containerisation and orchestration. * Relational data and canonical/JSON data contract design. * Design-system principles and component-library development. ## Description ICRV are seeking an exceptional Principal Engineer to own the architecture, design and hands-on delivery of desktop platform automating and streamlining trading desk workflows. This is a high-visibility player-coach role: you will apply deep technical expertise with architectural leadership, to transform desk operations and have a significant influence on the technology direction of this new platform working with offshore partners. It may evolve to include formal people management. Role Responsibilities * Act as the primary hands-on technical leader: architect the platform, write correctness-critical code, and set the engineering bar through your own output. * Own the technical direction of the ICRV greenfield project, developing high-performance, scalable, and robust solutions from first principles through to production operation. * Design for hard non-functional requirements: latency and responsiveness budgets as acceptance criteria, crash containment, least-privilege isolation between sub-applications. * Work effectively with a matrix management structure, taking designs through group-wide governance, while delivering business value ensuring adherence to group wide technology standards and mandates. * Mentor and coach other team members to achieve optimum performance and career growth. Work effectively to leverage offshore staffing vendors. * Establish AI-assisted development as a disciplined team practice using company wide tooling, workflow integration, and the review rigour that makes AI-generated code safe to ship. * Communicate technical trade-offs clearly to trading, compliance, infrastructure and middle-office stakeholders; manage risk and escalate honestly. * Identify and drive refactoring toward the target architecture as the platform grows. ## Related Videos - [Watch Tests Go Brrrr! : Getting Started with Cypress in ReactJS](https://www.wearedevelopers.com/videos/282-watch-tests-go-brrrr-getting-started-with-cypress-in-reactjs) - [Building Multi-Tenant ASP.NET Core Applications: Best Practices and Real-World Solutions](https://www.wearedevelopers.com/videos/1552-building-multi-tenant-asp-net-core-applications-best-practices-and-real-world-solutions) - [Tips and Tricks for Working with JSON](https://www.wearedevelopers.com/videos/1229-tips-and-tricks-for-working-with-json) - [Microservices architecture as a key element in building trading systems for global finance markets](https://www.wearedevelopers.com/videos/1196-microservices-architecture-as-a-key-element-in-building-trading-systems-for-global-finance-markets) - [Developing ASP.NET Core Microservices with Dapr: A practical guide](https://www.wearedevelopers.com/videos/1528-developing-asp-net-core-microservices-with-dapr-a-practical-guide) - [Agentic employees in world's most downloaded FinTech app](https://www.wearedevelopers.com/videos/100123-agentic-employees-in-world-s-most-downloaded-fintech-app) ## Related Articles - [Software Engineer Salary London](https://www.wearedevelopers.com/magazine/252-software-engineer-salary-london) - [The 12 Best Jobs for Software Engineers](https://www.wearedevelopers.com/magazine/401-the-12-best-jobs-for-software-engineers) - [Frontend Developer Salary in The UK](https://www.wearedevelopers.com/magazine/233-frontend-developer-salary-in-the-uk) - [Data Engineer Salary UK](https://www.wearedevelopers.com/magazine/253-data-engineer-salary-uk) - [Why Upskilling And Reskilling is Important For Developers](https://www.wearedevelopers.com/magazine/428-why-upskilling-and-reskilling-is-important-for-developers) - [The Most Popular IT Jobs on the Market](https://www.wearedevelopers.com/magazine/376-the-most-popular-it-jobs-on-the-market)