Senior Infrastructure Engineer

Radiant; Greater London; Hybrid; GBP 95,000 - 130,000; Full time

Job summary

Radiant is seeking a Senior Infrastructure Engineer to lead design and implementation of an AI-native cloud platform. You will build scalable, secure infrastructure, hypervisor tuning for HPC, and self-service tooling.

The role blends hands-on engineering with strong communication to enable teams to run AI/ML workloads reliably at scale. You’ll design virtualization, bare-metal provisioning, and cloud-native networking across hybrid environments, while driving CI/CD and IaC adoption.

Qualifications

• Hands-on experience delivering infrastructure at scale in cloud-native, HPC or AI-native environments.
• Extensive expertise in large-scale global deployments for AI-native, HPC, and cloud-native contexts.
• Strong Kubernetes fundamentals, including container networking and service meshes.
• Proficient in Infrastructure-as-Code tools like Terraform and Ansible; experience with CI/CD pipelines.
• Solid networking knowledge (TCP/UDP/DNS/BGP) and SDN solutions.
• Security hardening and governance across clusters and clouds.

Responsibilities

• Design & operate virtualization optimized for AI-native workloads, including HPC-oriented tuning.
• Build scalable platform capabilities for compute, storage, and networking demands.
• Provisioning, orchestration, and lifecycle management of bare-metal hardware.
• Maintain Unix/Linux expertise with secure, high-performance configurations.
• Deploy & manage Kubernetes clusters across hybrid/multi-cloud environments; implement CNIs and service meshes.
• Create CI/CD pipelines to automate infrastructure delivery; apply IaC across stacks.

Skills

Kubernetes fundamentals

IaC (Terraform, Ansible)

Automation in Go or Python

Networking protocols (TCP/UDP/DNS/BGP)

Observability tools (Prometheus, Grafa

Documentation & communication

Mentoring & leadership

Cloud-native platforms

Security hardening (RBAC, OPA)

Architectural design & collaboration

Tools

Terraform

Ansible

Kubernetes

CI/CD pipelines

Service meshes

Prometheus

Grafana

Vault

OPA Gatekeeper

SDN & networking tooling

Job description

About the Role

Location: UK (occasional office travel) | Employment Type: Full-time, Permanent | Reports to: Engineering Manager

We’re looking for a Senior Infrastructure Engineer in our Platform team to drive the architecture, design, and implementation of our next-generation AI-native cloud platform. You will implement scalable, resilient infrastructure and the self-service tooling that sits on top of it, working within an agreed architectural direction and contributing to how that direction evolves. You will combine strong hands-on engineering with clear communication, enabling teams to run HPC and AI/ML workloads reliably at scale.

What You’ll Do

Infrastructure Design & Virtualisation:

• Implement and operate virtualisation solutions optimised for AI-native workloads, including hypervisor tuning for HPC environments.

• Build platform capabilities that scale with customer demand for compute, storage and networking.

Bare-Metal and Operating System Management:

• Deliver provisioning, orchestration and lifecycle management of bare-metal hardware.

• Maintain strong Unix/Linux expertise, producing secure and performant configurations at scale.

Networking and High-Performance Storage:

• Implement high-performance, cloud-native storage and networking for demanding workloads.

• Apply solid working knowledge of networking protocols (TCP, UDP, DNS, encryption) and software-defined networking.

Kubernetes and Cloud-Native Platforms:

• Deploy and manage Kubernetes clusters across hybrid and multi-cloud environments, leveraging CNIs and service meshes.

• Build and maintain CI/CD pipelines that automate infrastructure delivery.

Security and Audit:

• Kubernetes security hardening (RBAC, PSA/PSP successors, network policies, admission controllers - OPA/Gatekeeper, Kyverino)

• Secrets management and rotation across clusters (Vault/OpenBao, sealed-secrets, external-secrets patterns)

• Supply chain security — image scanning, signed artifacts (cosign/sigstore), provenance attestation

• Apply least-privilege IAM patterns across bare-metal, cluster and cloud control planes.

Observability and Automation:

• Build and maintain observability pipelines covering logs, metrics and tracing.

• Create automation frameworks to reduce operational toil, streamline deployments, and enhance scalability using tools like Terraform, Ansible, Go, and Python.

Architecture & Solution Design:

• Analyse emerging technologies and assess their potential fit within our platform, considering scalability, security, and performance.

• Produce low-level designs and implementation plans for platform components, escalating cross-cutting architectural decisions appropriately.

• Collaborate with cross-functional teams to ensure successful implementation of infrastructure solutions.

• Participate in design reviews, offering constructive technical challenge.

• Write clear documentation and runbooks for the systems you build.

Collaboration and Leadership:

• Foster a ‘how do we achieve this?’ mindset, championing a positive, solution-oriented approach to challenges.

• Mentor less experienced engineers through pairing, code review and design feedback.

• Work with engineers across teams to deliver infrastructure work that lands end to end.

What You’ll Bring

• Hands-on experience delivering infrastructure at scale in cloud-native, HPC or AI-native environments.

• Demonstrated success in evaluating and adopting new toolsets and technologies.

• Extensive expertise in large-scale global infrastructure deployments, particularly in AI-native, HPC, and cloud-native environments.

• Strong Kubernetes fundamentals, including container networking (CNI) and service mesh technologies.

• Deep understanding of virtualisation and hypervisor technologies for high-performance workloads.

• Strong proficiency in networking protocols (TCP, UDP, DNS, BGP) and SDN solutions.

• Skilled in Infrastructure-as-Code (IaC) tools like Terraform, Ansible, and cloud orchestration frameworks.

• Hands-on coding experience in Go, Python, or similar languages for automation.

• Solid grasp of observability tools (Prometheus, Grafana) and distributed tracing systems.

• Strong communication and collaboration skills, with the ability to convey complex technical concepts to cross-functional teams.

• Demonstrate ability to create clear and concise documentation for infrastructure designs, processes and systems.

Nice to Have

• AI/ML workloads, GPU-accelerated systems, or HPC infrastructures, including GPU partitioning with MIG and the NVIDIA GPU Operator.

• Experience with RDMA fabrics such as InfiniBand or RoCEv2, and GPUDirect data paths.

• High-throughput distributed storage at scale, such as Ceph or a parallel filesystem.

• Familiarity with hybrid cloud and edge computing principles.

• Experience leading architecture initiatives in agile environments, working iteratively to deliver high-quality results.

Why Join Radiant

• Work on a rapidly scaling AI infrastructure business at the forefront of the industry

• Get broad exposure to a cutting-edge physical & software infrastructure stack

• Be part of a team where you’re genuinely valued and your work directly enables business decisions

• Develop your career in a Brookfield-backed company with resources, mentorship, and genuine growth opportunities