Senior C++ Engineer — Low-Latency Trading, Ownership

Reactive Markets; United Kingdom; Remote; GBP 100,000 - 170,000; Full time

Benefits offered by this job

Private health insurance

Pension

Life insurance

Dental/optical cashback

Cycle to work

Remote-friendly

Job summary

Reactive Markets Limited is seeking a C++ Software Engineer to build low-latency trading infrastructure on Linux. You will work on the core Switchboard platform—pricing engines, gateways, market-data, and the messaging layer—owning the full lifecycle from design to production support.

You’ll collaborate in a senior, small team, shipping reliable, high-performance systems. Occasional after-hours work for releases and incidents is expected, with a focus on quality and operational excellence.

Qualifications

• Strong C++ with Linux systems programming (3+ years).
• Comfortable working close to the metal and understanding what's underneath your code.
• Experience with performance-sensitive systems (profiling, optimisation, deterministic behaviour).
• Familiarity with networking fundamentals (TCP/UDP, socket programming).
• Go experience is a strong bonus; Python for scripting and tooling used across the platform.
• Git and shell scripting.
• Experience in financial services or trading technology is a plus but not essential.

Responsibilities

• Build low-latency trading infrastructure on Linux.
• Develop core components of the Switchboard trading platform: pricing engines, gateways, market-data, and messaging layer.
• Own the full lifecycle from design through production support and incident response.
• Investigate and fix production incidents, including during off-hours when needed.
• Contribute to tests, deployment pipelines, and operational documentation.

Skills

C++

Linux

Go

Python

Networking

Profiling

Git

Tools

AWS

Job description

Reactive Markets Limited is seeking a C++ Software Engineer to build low-latency trading infrastructure on Linux. You will work on the core Switchboard platform—pricing engines, gateways, market-data, and the messaging layer—owning the full lifecycle from design to production support.

You’ll collaborate in a senior, small team, shipping reliable, high-performance systems. Occasional after-hours work for releases and incidents is expected, with a focus on quality and operational excellence.