C++ Developer – High Frequency Trading (HFT Systems)

London - UK

Monthly Salary: Not Disclosed

Posted on: Yesterday

Vacancies: 1 Vacancy

Job Summary

C Developer High Frequency Trading (HFT Systems)

Join MARGO in the UK (London) High Performance Trading Environments

MARGO is a tech-native consultancy delivering elite software engineering expertise to the most demanding financial markets environments.

We operate in latency-critical trading contexts where performance determinism and predictability are core system requirements. Our consultants work in highly specialised trading environments designing systems that interact directly with exchanges and market venues under extreme time constraints.

Business Context

You will join a High Frequency Trading / Low Latency Trading environment within one of our partners (investment banks proprietary trading firms or market makers).

The teams design build and operate latency-sensitive trading systems directly connected to exchanges typically deployed in colocated environments.

These systems are characterised by:

Microsecond to sub-microsecond latency constraints

Deterministic and predictable execution paths

Minimal software and network overhead

Direct interaction with market data feeds and order gateways

Role Overview

We are looking for a C Software Engineer to work on latency-critical trading infrastructure.

The role is strongly engineering-driven and focuses on speed predictability and control of execution rather than functional feature delivery.

Depending on the environment the role may also involve interaction with C# components used outside the ultra-latency-critical execution path.

Key Responsibilities

Core HFT Engineering

Design develop and optimise ultra-low latency C trading components

Work on critical execution paths for market data processing and order routing

Implement lock-free and wait-free algorithms

Optimise memory allocation cache locality and CPU utilisation

Reduce jitter and tail latency

System-Level & Hardware-Aware Optimisation

Analyse and optimise CPU behaviour (branch prediction cache misses NUMA effects)

Work closely with infrastructure and network teams on kernel bypass and user-space networking

Profile systems at instruction-level and hardware-counter granularity

Production Ownership

Ensure correctness determinism and stability of production trading systems

Participate in production releases and live deployments

Investigate latency regressions and production anomalies

Maintain rigorous operational discipline

Use of C# (Non-Critical Path)

C# may be used outside the latency-critical execution path for:

Monitoring and control tooling

Configuration and orchestration services

Risk guards limits and kill-switch mechanisms

Real-time dashboards and operational analytics

C# is not used on the execution path and does not replace core C expertise.

Technical Environment

Core Technologies

Modern C (C17/20)

- Lock-free programming

- Custom memory allocators

- Zero-copy architectures

Linux (advanced / low-level understanding)

- CPU pinning

- Huge pages

- NUMA architectures

Networking

- TCP / UDP market data feeds

- Multicast

- Kernel bypass technologies (DPDK Solarflare Onload or equivalent)

Latency & Performance Tooling

CPU profilers and hardware performance counters

Packet capture and latency measurement tools

Exchange simulators and market data replay tools

Required Experience & Skills

Essential

Strong experience in C development for performance-critical or low-latency systems

Proven background in HFT or ultra-low latency trading environments

Deep understanding of CPU architecture caches and memory models

Strong knowledge of concurrency memory ordering and Linux internals

Experience working close to hardware and network layers

Strong production mindset and sense of ownership

Highly Valued

Exposure to C# in trading control or monitoring systems

Experience with market data feed handlers or order gateways

Prior exposure to market making or proprietary trading environments

Experience with FPGA-assisted or hybrid architectures

Why Join MARGO

Access to elite HFT and ultra-low latency trading environments

Technically extreme and intellectually demanding engineering assignments

Clear separation between execution-critical and supporting systems

Human-sized consultancy with very high technical standards

Long-term positioning on rare high-value low-latency engineering skillsets

Important Note

This role is not suitable for candidates with a C#-only background.

Core execution systems are implemented in C.

Please note - We do not offer visa sponsorship for this position.

Interested Motivated Apply on our website or at @

We may use artificial intelligence (AI) tools to support parts of the hiring process such as reviewing applications analyzing resumes or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed please contact us.

Required Experience:

C Developer High Frequency Trading (HFT Systems)Join MARGO in the UK (London) High Performance Trading EnvironmentsMARGO is a tech-native consultancy delivering elite software engineering expertise to the most demanding financial markets environments.We operate in latency-critical trading contexts...