Principal Engineer

Harrington Starr; Greater London; Hybrid; GBP 126,000 - 154,000; Full time

Benefits offered by this job

Private Medical Insurance

Life Insurance

Pension

Employee Assistance Programme

25 days annual leave

Job summary

Harrington Starr in London is partnering with a leading financial technology firm to hire a Principal C# Software Engineer. This senior technical leadership role focuses on real-time trading technology, platform modernisation and re-architecture, blending hands‑on engineering with architecture guidance and mentoring.

You will shape the technical roadmap, lead platform development through to production, drive improvements in scalability, observability, CI/CD and developer productivity, and

Qualifications

• Strong C#/.NET software engineering experience.
• Strong understanding of real-time and low-latency architecture.
• Experience leading modernisation, migration or re-architecture programmes.
• Experience with cloud-native architectures, APIs, event-driven systems and CI/CD.
• Financial markets experience, ideally across electronic trading, OTC derivatives, fixed income, FX or similar, with strong technical leadership skills.

Responsibilities

• Shape the technical roadmap and platform re-architecture strategy.
• Lead platform development through to production and improve scalability, resilience and performance.
• Drive improvements across automation, observability, CI/CD and developer productivity.
• Partner with Engineering, Product and Operations to deliver practical technical solutions.
• Mentor engineers and champion engineering standards, best practices and continuous improvement.

Skills

C#/.NET

real-time architecture

modernisation / re-architecture

cloud-native architectures

APIs / event-driven systems

CI/CD

leadership / mentoring

financial markets experience

Job description

Salary: Up to £140,000 + Bonus & Benefits

Harrington Starr is partnering with a leading financial technology firm to hire a Principal C# Software Engineer in London.

This is a senior technical leadership role focused on real-time trading technology, platform modernisation and re-architecture, combining hands-on engineering, architecture and mentoring.

The Role:

• Shape the technical roadmap and platform re-architecture strategy
• Lead platform development through to production and improve scalability, resilience and performance
• Drive improvements across automation, observability, CI/CD and developer productivity
• Partner with Engineering, Product and Operations to deliver practical technical solutions
• Mentor engineers and champion engineering standards, best practices and continuous improvement

What We're Looking For:

• Strong C#/.NET software engineering experience
• Strong understanding of real-time and low-latency architecture
• Experience leading modernisation, migration or re-architecture programmes
• Experience with cloud-native architectures, APIs, event-driven systems and CI/CD
• Financial markets experience, ideally across electronic trading, OTC derivatives, fixed income, FX or similar, with strong technical leadership skills
• Up to £140,000 base salary + discretionary bonus
• 25 days annual leave + bank holidays
• Hybrid and flexible working
• Private Medical Insurance and Life InsurancePension and Employee Assistance Programme