Senior Infrastructure EngineerRemote (UK-based), with occasional on-site work at our data centres | Full-TimeAbout UsReactive Markets is the 2026 OTC Trading Platform of the Year (Risk.net). Our network handles over $75 billion in daily trading volumes across FX, Equities, and Cryptocurrency, connecting 50+ 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.The RoleWe’re looking for a Senior Infrastructure Engineer to help run and grow the network and cloud estate behind our trading platform. Networking in our colocation data centres is the core of the role. The estate spans London, New York and Singapore, and from Q1 2027 a new Tokyo data centre.This is a hands-on role in a small, expert infrastructure team. You’ll work closely with our Head of Infrastructure, following problems from the cross-connect through hosts, containers and AWS. You’ll also help keep infrastructure delivery on track, from timelines and reporting to working closely with our TechOps team.What You’ll Work OnLow-latency networking across our colocation sites: switching and routing, cross-connects, BGP peering with liquidity providers and clients, and the fabric that carries our trading trafficBringing new sites to application-ready, starting with TokyoOur hybrid connectivity into multi-region AWS, including Direct Connect, routing and failoverLinux hosts and containers on the critical path, with every change made through code (Ansible, Git, Terraform), never by handMonitoring and alerting that catches problems before clients do, plus runbooks and post-incident reviews that someone else can followPlanning and capacity: forecasting growth, setting timelines and reporting progress to TechOps and engineeringWhat We Need4+ years running production infrastructure in a latency-sensitive environment, such as HFT, an exchange, market data or bank trading infrastructureStrong networking: hands-on routing and switching (MLAG, LACP, VLANs), BGP in production, and a solid grasp of low-latency behaviour such as buffers, microbursts and congestion handlingColocation experience: cabinets, cross-connects, remote hands and vendor managementSolid Linux (RHEL) and TCP/IP, and the ability to trace a problem from the wire to the applicationInfrastructure as code and containers as your default way of workingWorking knowledge of AWS networking, and the confidence to pick up the rest of our stack. Networking depth matters more to us than any particular cloud or platform toolingMethodical, evidence-led troubleshooting and clear documentationA strong plus:Project management experience: owning timelines, reporting progress, and working with ops teams to hit deadlinesKernel bypass (Onload/ef_vi), PTP and time synchronisationExperience bringing up a new colo siteFIX protocol or OTC FX market knowledgePython for toolingWorking pattern: Infrastructure changes are often scheduled outside trading hours, including weekends, and the team shares an on-call rota. We’re a team with flexible hours, so time worked out of hours is taken back during the week. Day-to-day work is remote, with occasional visits to our data centres, most often in London (Slough).What You GetReal ownership of a live global trading network, hands-on, with few layers of processA build-out year, with a new Tokyo data centre in Q1 and more growth aheadA senior seat in a small, expert team where your changes ship and are measuredCompetitive package — up to 38 days leave (inc. bank holidays), private health insurance, pension, life insurance, dental/optical cashback, cycle to work, socials and offsitesRemote-friendly working with flexibility around out-of-hours workGrowth as the estate scalesWe believe in transparency, honest feedback and writing things down, and we aim to build systems that don’t depend on the heroics of individuals.Our Hiring ProcessWe keep our process focused and respectful of your time. Our process follows three stages:Stage 1: Initial Conversation with Talent Acquisition Format: Video call, ~30-45 minutesStage 2: Technical Deep Dive with our Head of Infrastructure Format: Video call, interactive session, ~90 minutesStage 3: Leadership Conversation with our CDO Format: Video call, ~45 minutesWhat to expect in each stage will be explained by Talent Acquisition if you’re invited to interview. Throughout the process, we aim to keep momentum with no unnecessary delays between stages, and feedback typically comes within a few business days.How to ApplyPlease apply directly via this job posting — all applications, including those submitted via LinkedIn, are managed through our applicant tracking system, so you’ll always land in the same place regardless of where you found this role.Right to Work: Candidates must have the existing right to work in the UK. We are not currently able to offer visa sponsorship for this role.Equal Opportunities: Reactive Markets is an equal opportunities employer. 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.Reasonable Adjustments: If you need any adjustments or support during the application or interview process, please let us know — we’re happy to accommodate.Data Protection: By applying, you consent to Reactive Markets processing your personal data for recruitment purposes, in line with our privacy policy.#Hiring #Infrastructure #Networking #LowLatency #TradingTechnology #FinTech #Remote #ColocationFind more English Speaking Jobs in United Kingdom on Arbeitnow