Platform Site Reliability Engineer

ABOUT RADIANT Radiant is redefining how AI infrastructure is built. We design and operate AI-native cloud platforms engineered for sovereignty, performance, and scale. Our infrastructure powers GPU-native workloads, multi-tenant control planes, and high-performance AI systems designed for the most demanding environments. We are not building a generic cloud. We are building purpose-built AI infrastructure - from powered land, to compute, to software . As we scale our platform and expand our engineering organisation, we are looking for leaders who can build strong teams, uphold high standards, and deliver reliably at pace. Role Responsibilities - Deploy and Manage Kubernetes Clusters, deployed at scale to support AI centric workloads, across both our bare metal clusters and via trusted partner infrastructure - Develop Kubernetes Manifests and Operators: Facilitate application deployments and maintain Kubernetes-native services for networking, storage, security, identity and infrastructure management - Optimize Linux system configuration including kernel, driver, filesystem and services to support workloads running via our orchestration layer - Build and maintain automation scripts and infrastructure as code to support platform lifecycle, as well as simplifying troubleshooting for Incident resolution and provision of tooling for our support organisation - Apply ITSM frameworks: Incident, Major Incident, Change Management, and service improvement. - Maintain and enhance Radiant’s observability stack: Prometheus, Grafana, and custom monitoring integrations - Operate and support services in 24x7 production environments, including on-call rotation - Contribute to Incident postmortem analyses, root cause analysis, document learnings, and automate remediations - Mentor junior engineers and act as an Operational requirements consultant to other departments - Communicate technical decisions clearly to non-technical stakeholders and customers - Uphold a culture of: do, document, automate - Willingness to cross train with Platform Engineering/Platform SRE to fully support both our infrastructure and platform stacks. - Willingness to cross train with HPC Engineering, supported by NVIDIA to enhance our HPC supportability offering Requirements - 5+ Years Proven experience in globally scaled, performance-intensive environments operating to a 24/7 support model in an SRE or equivalent role - 3+ years experience in both running, deploying and optimising orchestration platforms with a strong emphasis on Kubernetes - Expert-level Linux administration, especially Ubuntu distributions - Proficiency in system tuning, disk I/O optimization, and hardware-level performance tweaks - Strong networking fundamentals: TCP/IP, DNS, DHCP, VLANs, routing, switching - Strong experience with API interrogation - Strong experience with infrastructure scripting and automation (Bash, Python, Ansible) - Deep understanding of observability principles and tools (Prometheus, Grafana preferred) - Strong grasp of ITSM and service operation best practices - Excellent communication and mentorship skills - Comfortable interfacing with internal stakeholders and external customers - Bonus: Knowledge of running AI workloads via orchestration platforms Bonus Requirements - Bachelor or Masters Level degree in Computer Science, Engineering or related field, or equivalent experience. - LPIC Certifications - ITIL Foundation level qualification or equivalent experience - Certified Kubernetes Administrator (CKA) Qualities we look for: - You approach problems with a systems mindset - balancing practical execution with long-term scalability - You elevate the team, setting high standards for technical quality and engineering excellence. - You hold yourself and others accountable - giving direct feedback and expecting the same - You take initiative, owning challenges end-to-end and proactively driving solutions. - You invest in others, mentoring to build both capability and confidence. Why