Senior Infrastructure Engineer

Reactive Markets is the 2026 OTC Trading Platform of the Year, handling over $75 billion in daily trading volumes across FX, Equities, and Cryptocurrency, connecting 50+ of the world’s leading liquidity providers.

About the Role

We are seeking a Senior Infrastructure Engineer to manage and expand the network and cloud infrastructure supporting our trading platform. This role focuses on low-latency networking across colocation data centers in London, New York, Singapore, and a new Tokyo data center launching in Q1 2027.

The role involves hands-on work in a small, expert infrastructure team, collaborating closely with the Head of Infrastructure. Responsibilities include troubleshooting network issues, managing infrastructure delivery, and ensuring seamless operations with the TechOps team.

Key Responsibilities

• Design and maintain low-latency networking across colocation sites, including switching, routing, cross-connects, and BGP peering with liquidity providers and clients.

• Bring new sites to application-ready status, starting with the Tokyo data center.

• Manage hybrid connectivity into multi-region AWS, including Direct Connect, routing, and failover mechanisms.

• Work with Linux hosts and containers on the critical path, ensuring every change is made through Infrastructure as Code (Ansible, Git, Terraform) rather than manual intervention.

• Develop and maintain robust monitoring and alerting systems to detect issues before they impact clients, along with comprehensive runbooks and post-incident reviews.

• Plan and manage capacity, forecasting growth, setting timelines, and reporting progress to TechOps and engineering teams.

Requirements

• 4+ years of experience running production infrastructure in a latency-sensitive environment, such as HFT, exchanges, market data, or bank trading infrastructure.

• Proficient in networking, including hands-on experience with routing and switching (MLAG, LACP, VLANs), BGP in production, and understanding of low-latency behaviors like buffers, microbursts, and congestion handling.

• Experience with colocation, including cabinets, cross-connects, remote hands, and vendor management.

• Strong knowledge of Linux (RHEL) and TCP/IP, with the ability to trace problems from the wire to the application.

• Experience with Infrastructure as Code and containers as the default way of working.

• Working knowledge of AWS networking, with the ability to quickly adapt to other tools in the stack.

• Methodical, evidence-led troubleshooting and clear documentation practices.

A strong plus:

• Experience in project management, including owning timelines, reporting progress, and collaborating with ops teams to meet deadlines.

• Experience with kernel bypass technologies (Onload/ef_vi), PTP, and time synchronization.

• Experience bringing up a new colocation site.

• Familiarity with the FIX protocol or OTC FX market knowledge.

• Experience with Python for tooling.

Working Pattern: Infrastructure changes are often scheduled outside trading hours, including weekends, with a shared on-call rota. The team operates with flexible hours, ensuring out-of-hours work is compensated during the week. Day-to-day work is remote, with occasional visits to data centers, primarily in London (Slough).

Benefits

• Ownership of a live global trading network with hands-on responsibilities and minimal process layers.

• Opportunity for growth as the infrastructure estate scales, including the launch of a new Tokyo data center in Q1 2027.

• A senior role in a small, expert team where your contributions directly impact the systems.

• Competitive package including up to 38 days leave (including bank holidays), private health insurance, pension, life insurance, dental/optical cashback, cycle-to-work scheme, social events, and offsites.

• Remote-friendly work environment with flexibility around out-of-hours work.