HPC Infrastructure Site Reliability Engineer

📋 Job Overview

We’re a fast-growing GPU-as-a-Service provider, delivering scalable, high-performance compute infrastructure purpose-built for AI and HPC workloads. Operating across global data centres, we run mission-critical environments where uptime, throughput, and ultra-low latency are non-negotiable.

🏢 About Radiant

Join a team operating some of the world’s most advanced high-performance computing infrastructure. As a HPC Infrastructure SRE, you’ll work hands-on with cutting-edge GPU and CPU platforms — including the latest NVIDIA architectures — powering dense, large-scale compute environments used for AI, machine learning, and next-generation workloads.

🎯 The Role

We are looking for a senior Infrastructure Site Reliability Engineer with deep experience operating large-scale distributed systems and recent hands-on expertise in high-performance computing (HPC) and AI infrastructure. This is an operations-first SRE role, working in a 24/7/365 on-call environment, responsible for ensuring reliability, performance, and continuous improvement of mission-critical infrastructure. This role sits within a cross-functional organisation spanning network engineering, infrastructure SRE, Platform SRE, infrastructure tooling engineers (software) and data centre operations.

✅ Key Responsibilities

• Operate and improve high-density AI/HPC infrastructure in a 24/7 production environment
• Participate in a 24x7x365 on-call rotation, supporting mission-critical systems and incident response
• Troubleshoot complex issues across compute, networking, storage, and orchestration layers in GPU-accelerated environments
• Lead performance evaluation, testing, and operational acceptance of new HPC infrastructure before production release
• Drive continuous service improvement (CSI), reducing operational toil, increasing automation, and improving reliability, consistency, and operational efficiency across the platform
• Build and maintain infrastructure automation and tooling (IaC and scripting) to improve reliability and operational efficiency
• Optimise Linux systems for performance, including kernel, BIOS/firmware, and storage tuning for HPC workloads
• Configure and operate bare-metal infrastructure using IPMI, iLO, iDRAC, Redfish, and related tooling
• Partner with infrastructure tooling and observability teams to improve telemetry, alerting, and system visibility at scale
• Own ITIL-aligned processes across Incident, Major Incident, Problem, and Change Management, ensuring strong execution and continuous improvement
• Lead root cause analysis and ensure corrective actions are implemented and automated where possible
• Play a key role in designing and delivering future HPC cluster and site builds, shaping global consistency and operational standards
• Collaborate closely with Platform Engineering, Network Engineering, Infrastructure Tool

🎁 Benefits

This is an opportunity to build expertise at the forefront of modern infrastructure, where reliability, scale, and performance matter every day. You’ll collaborate with experienced engineers across a globally distributed organisation that values openness, inclusion, technical excellence, and continuous learning. We move quickly, solve meaningful challenges, and give people the space to make an impact. If you thrive in fast-paced environments, enjoy working with advanced technology, and want to help shape the future of high-performance compute, you’ll find both challenge and opportunity here.

You can also expect:

• Exposure to industry-leading GPU and AI infrastructure
• Opportunities to grow alongside a rapidly scaling global business
• A collaborative, inclusive, and supportive engineering culture
• Real ownership and the ability to influence operational excellence
• Work that sits at the intersection of people, performance, and technology
• A modern, flexible, globally connected workplace with ambitious goals