C++ Software Engineer (Contract) – £300–£400/day – Outside IR35

You'll be working for a Fintech company as an experienced C++ Software Engineer. Joining the development team on a 9month contract (OUTSIDE IR35).
This role focuses entirely on modern C++ engineering within a high-performance Linux environment.

You’ll work across core C++ components, toolsets, and performance-critical systems, collaborating with senior engineers to enhance and maintain a sophisticated technical product suite. The work is varied, technical, and ideal for someone who enjoys solving low-level and high-performance coding challenges.

This position does not require prior experience in financial services or trading systems, but if you have it, then great. If not, we are happy for you to learn this on the job.

Role Responsibilities

• Develop modern, production?grade C++ features and components
• Work with multi?threaded, high?performance systems
• Contribute to design discussions, code reviews, and technical improvements
• Implement networking?related logic (sockets, data transfer, system communication)
• Analyse and optimise existing code for efficiency and performance
• Collaborate closely with an experienced engineering team on complex technical challenges

Required Skills

• 5+ years’ experience developing C++ in production
• Strong hands?on experience with Linux environments
• Solid understanding of:
  • Multithreading / concurrency
  • Networking fundamentals (sockets, routing, etc.)
• Familiarity with Python (for internal tools or scripting)
• Experience with QT6
• Basic SQL
• Clear verbal and written communication skills

Desirable (Not Essential)

• Financial service experience
• Background in performance?critical or low?latency systems

Contract Details

• Rate: £300–£400 per day
• IR35: Outside IR35
• Duration: 9 months
• Location: London hybrid (some onsite required)

Why Apply?

• Fully engineering-focused role (no QA responsibilities)
• Outside IR35 flexibility
• Opportunity to get into Financial Service and Low Latency Trading environments. 
• Work alongside highly skilled senior developers
• Exposure to challenging, modern C++ work
• Friendly, collaborative technical environment