Skills

Communication Python SQL Networking Linux C++

Job Specifications

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 9‑month 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

About the Company

Harrington Starr is a multi-award winning financial technology recruitment business based in London, Belfast and New York City. Founded in 2010, we are specialists in technology, change & transformation and sales recruitment and have helped clients and candidates across 5 continents. Our diverse range of clients include banks, hedge funds, vendors, service providers, payment providers, asset managers, start-ups, disruptors and many more. The one thing they have in common though is that they trust Harrington Starr with their... Know more