Senior C++ Developer

Position: Senior C++ Developer (Permanent)
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