Principal Software Engineer – C#

Overview

In this Principal Engineer role you will own the architecture and hands-on delivery of a new desktop trading platform that streamlines desk workflows. You’ll lead technical direction for a greenfield project, working with offshore partners, and ensuring high performance, resilience, and governance. You’ll mentor engineers, champion AI-assisted development, and communicate trade-offs to traders and stakeholders. This role offers visibility, impact on platform direction, and the chance to shape how front-office operations are executed.

Responsibilities

• Architect the desktop trading platform and deliver correctness-critical code
• Lead the technical direction of a greenfield project from design to production
• Design for latency, crash containment, and least-privilege isolation
• Navigate governance and standards within a matrix, delivering business value
• Mentor team members and coordinate with offshore staffing
• Establish AI-assisted development practices and tooling
• Communicate trade-offs to trading, compliance, infrastructure, and middle-office
• Drive refactoring toward the target architecture as the platform evolves

Key requirements

• 10+ years in financial services building complex front-office trading systems
• Proven technical leadership on multi-year transformation programmes
• Hands-on SDLC experience
• Practical experience with AI tools across development lifecycle and safe AI-generated code
• Excellent written and verbal communication in a global, matrix organisation
• Degree in Computer Science, Engineering, Mathematics, Physics, or relevant analytical discipline
• Understanding of relative-value execution and futures/UST market structures
• Experience with execution/connectivity protocols (FIX or equivalent) in interdealer or execution-desk context
• Knowledge of 24-hour, multi-region trading operations
• Strong background in C# / .NET (ASP.NET Core) and back-end service design
• Experience with event-driven back-end systems and desktop apps hosting web content
• Front-end literacy (React, TypeScript, Node) for architecture review and collaboration
• Understanding of security, identity/access management, and least-privilege boundaries
• Familiarity with modern build pipelines and governance/architecture-review processes

• Excellent communication in cross-functional settings
• Self-motivated and proactive in a matrix organisation
• Mentoring and people development
• C# / .NET (LTS) backend services, ASP.NET Core
• Event-driven, service-oriented architectures, message brokers
• Desktop apps hosting web content (Electron, Tauri) or similar

…