Senior C++ Developer

Senior C++ Developer – High-Performance Messaging Systems

£180,000–£200,000 | London | Hybrid

Ncounter is supporting the growth of a high-performing engineering team responsible for building and evolving one of the most sophisticated messaging platforms in the capital markets space. This is a senior-level C++ role focused on performance, reliability, and scale, sitting at the heart of a globally distributed trading environment.

You’ll take ownership of a large, in-house C++ codebase that underpins hundreds of applications and mission-critical data flows. The work is deeply technical, solving problems around low latency, throughput, concurrency, and resilience, while operating in a predominantly Linux environment with Python used for tooling, libraries, and integration.

What you’ll be working on

Designing and enhancing high-performance C++ messaging libraries used across global trading systems Optimising multithreaded, low-latency components in Linux environments Supporting and evolving APIs used by teams working in C++, Python, and other languages Working closely with infrastructure and platform teams to ensure reliability at scale Troubleshooting, testing, and performance tuning across complex distributed systems

What we’re looking for

Strong commercial experience in modern C++ within performance-critical systems Deep understanding of Linux, including deployment, debugging, and runtime behaviour Practical Python experience for scripting, tooling, or API interaction Experience building or supporting high-throughput, low-latency platforms Solid grounding in concurrency, memory management, and systems-level problem solving

This is a genuinely technical role with real ownership, long-term scope, and exposure to complex engineering challenges that few environments can offer.

If you’re a senior C++ engineer who enjoys working close to the metal, values clean systems design, and wants to build technology that truly matters, get in touch with Ncounter for a confidential conversation.