C++ Engineer

Software Developer, C++ / Electronic Trading London | Hybrid | Permanent

Ncounter is supporting the growth of a specialist electronic trading technology team responsible for building and enhancing high-performance systems operating across global financial markets. We are looking for an experienced Software Developer with strong C++ skills and a background working on low-latency trading technology.

You'll work on business-critical applications including matching engines, FIX gateways and real-time trading systems, where performance, availability and efficient processing are fundamental. This is a hands‑on development role with considerable exposure to C++, alongside Java, Python and JavaScript within a predominantly Linux environment.

• Designing and developing high-performance matching engines, FIX gateways and electronic trading applications
• Building low-latency, multithreaded systems using C++ and Java
• Processing real-time market and trading data through highly available systems
• Developing efficient in‑memory data structures, lock‑free queues and circular buffers
• Working with TCP/IP, UDP, multicast and other networking technologies
• Troubleshooting, profiling and optimising performance‑critical production applications
• Supporting automated testing, Dev Ops practices and CI/CD pipelines
• Working closely with trading, product and infrastructure teams throughout the development lifecycle

• 5+ years of professional software development experience
• Strong C++ development skills, ideally alongside commercial Java experience
• Hands‑on FIX protocol experience within electronic trading
• Experience building low‑latency, high‑frequency or performance‑critical systems
• Strong Linux knowledge covering multithreading, sockets, IPC and system‑level behaviour
• Good understanding of concurrency, memory management and in‑memory optimisation
• Knowledge of NUMA architectures and performance‑focused programming techniques
• Experience with networking protocols including TCP/IP, UDP, unicast and multicast
• Python, SQL and relational database experience would be useful

This is an opportunity to work close to the core of electronic trading, solving challenging engineering problems where software performance has a direct business impact.