Principal Engineer

Harrington Starr; Newcastle upon Tyne; Hybrid; GBP 99,000 - 121,000; Full time

Benefits offered by this job

Discretionary bonus

Hybrid work

Private medical insurance

Pension

Job summary

Harrington Starr partners with a leading financial technology firm to hire a Principal C# Software Engineer in Newcastle. The role focuses on real‑time trading technology, platform modernisation and re‑architecture, blending hands‑on engineering with architecture and mentoring.

You will shape the technical roadmap, design low‑latency distributed systems and lead development through to production, driving scalability, resilience and performance while improving automation and CI/CD practices.

Qualifications

• Strong C#/.NET software engineering experience.
• Proven experience building scalable, high-performance distributed systems.
• 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.
• Design and evolve low-latency, event-driven distributed systems.
• 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

scalable distributed systems

real-time low-latency

modernisation/re-architecture

cloud-native architectures

APIs/CI-CD

financial markets experience

Job description

Principal Engineer

Newcastle | Hybrid | Permanent

Salary: Up to £110,000 + Bonus & Benefits

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

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
• Design and evolve low‑latency, event‑driven distributed systems
• 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
• Proven experience building scalable, high‑performance distributed systems
• 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

Benefits

• Up to £110,000 base salary + discretionary bonus
• 25 days annual leave + bank holidays
• Hybrid and flexible working
• Private Medical Insurance and Life Insurance
• Pension and Employee Assistance Programme

If you’re a Principal‑level C# engineer looking to shape architecture, modernise complex platforms and work on real‑time financial technology, we’d love to hear from you.