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

MARGO

Greater London

On-site

GBP 140,000 - 210,000

Full time

14 days+

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Benefits offered by this job

Access to elite HFT trading environments

Intellectually demanding engineering assignments

Long-term career in low-latency skills

Job summary

A leading tech consultancy in London is seeking a C++ Software Engineer to work on latency-critical trading infrastructure. The role focuses on developing ultra-low latency trading systems in a high-performance trading environment. Candidates should have significant experience in C++ development and a strong understanding of CPU architectures. The position is not suitable for those with a C#-only background. The consultancy offers intellectually demanding engineering assignments and doesn’t provide visa sponsorship.

Qualifications

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 close to hardware and network layers.
Own production readiness and sense of ownership.

Responsibilities

Design, develop, and optimise ultra-low latency C++ trading components.
Work on critical execution paths for market data processing and order routing.
Ensure correctness, determinism, and stability of production trading systems.
Analyse memory allocation, cache locality and CPU utilisation.
Collaborate with infrastructure teams on kernel bypass and low‑level networking.
Own production releases and live deployments; investigate latency regressions.

Skills

C++ development

Low-latency systems

Concurrency and memory ordering

CPU architecture knowledge

Concurrency understanding

Networking

Lock-free programming

Market data feeds

Kernel bypass

C# exposure

Tools

Linux

CPU profilers

Market data feeds

Job description

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.

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++ (C++17/20)
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