Software Specialist

Reactive Markets Limited; United States; Remote; USD 79,000 - 119,000; Full time

Benefits offered by this job

Private health insurance

Pension

Life insurance

Dental/optical cashback

Cycle to work

Socials and offsites

Job summary

Reactive Markets Limited seeks a C++ Software Engineer to help build low-latency trading infrastructure on Linux. You will work on core components of the Switchboard platform, including pricing engines, connectivity gateways, and market-data systems.

Remote-friendly, UK-based full-time role with opportunities to grow into senior technical leadership. The role emphasizes performance-sensitive development, strong C++ coding on a modern cloud-native stack, and collaboration across tooling,

Qualifications

• 3+ years of strong C++ engineering
• Experience with Go and Linux in a modern cloud-native stack
• Familiarity with networking fundamentals (TCP/UDP) and high-performance systems
• Python scripting and tooling for automation and data analysis

Responsibilities

• Build low-latency trading infrastructure on Linux
• Develop core components of the Switchboard platform and pricing engines
• Create reliable connectivity gateways and market-data systems
• Contribute to testing, deployment, and incident response

Skills

C++

Go

Python

Linux

Networking TCP/UDP

Performance tuning

Observability

Job description

you support it in production, and you improve it. Occasional hours outside the normal working day are required for production releases, scheduled maintenance windows, and Level 3 support during critical incidents. Modern C++20 and Go on Linux a modern software stack based on open source Cloud-native infrastructure on AWS with colocation in key data centres Market-data and reference-data pipelines across multiple asset classes Observability and monitoring dashboards, alerting, and metrics that make system behaviour visible Strong C++ with Linux systems programming (3+ years) Experience with performance-sensitive systems (profiling, optimisation, deterministic behaviour) Familiarity with networking fundamentals (TCP/UDP, socket programming) Go experience is a strong bonus we use Go extensively for microservices and command-line tooling, and you'll be expected to work with it internally. If you don't know it yet, strong C++ engineers pick it up quickly Python for scripting, automation testing, and data analysis used across the platform for tooling and operational workflows Experience in financial services or trading technology is a plus but not essential You ship. Clear, proactive communication especially when things go wrong is essential You care about quality. You embrace AI tooling. We use AI tools (Claude, Gemini) to amplify our engineering capability from code review and debugging to incident investigation and documentation. Real problems trading systems where performance is measured in microseconds, not user clicks

Competitive package up to 30 days leave + bank holidays, private health insurance, pension, life insurance, dental/optical cashback, cycle to work, socials and offsites Remote-friendly work from home with flexibility. Growth career progression to senior roles, performance specialisation, or technical leadership. We believe in transparency, honest feedback, and writing things down. We frame AI as empowering people removing toil, amplifying capability, enabling higher-value work.

Stage 1: Initial Conversation with Talent Acquisition

• Video call, 30-45 minutes
• Video call, 30-45 minutes
• Video call, 60 minutes
• Video call, interactive session, 60 minutes

What to expect in each stage will be explained by Talent Acquisition if you're invited to interview.

We welcome applications from all qualified candidates regardless of age, disability, gender reassignment, marriage or civil partnership, pregnancy or maternity, race, religion or belief, sex, or sexual orientation.

C++ Software Engineer Remote (UK-based) Full-Time

Reactive Markets is the 2026 OTC Trading Platform of the Year ( ). Our network handles over 50 billion in daily trading volumes across FX, Equities, and Cryptocurrency, connecting 40+ of the world's leading liquidity providers. We build trading systems that operate at the edge of what's technically possible where nanoseconds matter and a dropped message costs real money. Our engineering team is small, senior, and deeply invested in the craft of building cutting edge, reliable, high-performance systems. We're looking for a C++ Software Engineer who wants to build low-latency trading infrastructure on Linux. You'll work on the core components of our Switchboard trading platform pricing engines, connectivity gateways, market-data systems, and the messaging layer that ties them together. You build it, you test it, you deploy it