Low-Latency C++ Engineer for Electronic Trading

Ncounter Limited; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Job summary

Ncounter Limited in London is seeking an experienced Software Developer with strong C++ skills to help build high-performance, low-latency trading systems. You will work on matching engines, FIX gateways, real-time data processing, and collaborate across trading, product and infra teams; hybrid work model with on-site days.

The role requires 5+ years in software development and proven multithreading, Linux, and networking proficiency.

Qualifications

• 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.

Responsibilities

• 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, DevOps practices and CI/CD pipelines.
• Working closely with trading, product and infrastructure teams throughout the development lifecycle.

Skills

C++

Java

Low-latency

Multithreading

Linux

Networking

FIX protocol

Python

Job description

Ncounter Limited in London is seeking an experienced Software Developer with strong C++ skills to help build high-performance, low-latency trading systems. You will work on matching engines, FIX gateways, real-time data processing, and collaborate across trading, product and infra teams; hybrid work model with on-site days.

The role requires 5+ years in software development and proven multithreading, Linux, and networking proficiency.