Senior On-Prem Platform Engineer: Kubernetes & Storage

Referment; Greater London; On-site; GBP 110,000 - 170,000; Full time

Job summary

Referment is seeking an experienced on-prem platform engineer to design, build, and operate the Kubernetes platform and VM fabric in a high-stakes, low-latency trading environment.

The role covers full lifecycle management of on-prem Kubernetes clusters, including bootstrapping, upgrades, and scale, with strong emphasis on storage, networking, and observability. Collaboration with data center and network teams is essential.

Qualifications

• Production experience running self-managed, on-premises Kubernetes, including operating etcd and the control plane.
• Hands-on experience designing and operating a Linux KVM/libvirt-based VM fabric, ideally from an early stage.
• Strong Linux systems administration background, including networking, storage, service management, kernel tuning, and troubleshooting under pressure.
• In-depth knowledge of Kubernetes networking and storage, including CNI internals, CSI drivers, and distributed storage systems such as Ceph or Longhorn.
• Experience with infrastructure as code and configuration management, including Terraform, Ansible, or Packer; GitOps workflows; and CI/CD pipelines.
• Familiarity with observability stacks such as Prometheus/Grafana and ELK/Loki, and using them to diagnose infrastructure issues without cloud-native tooling.
• Familiarity with hardening standards, RBAC, network segmentation, and secrets management.
• Strong troubleshooting skills across the hypervisor, OS, network, container runtime, and Kubernetes control plane.
• Strong written and verbal communication skills for working with distributed or hybrid teams.
• Будет плюсом: service meshes, bare-metal Kubernetes provisioning, experience in regulated or air-gapped/restricted-network environments, contributions to open-source infrastructure tooling, use of AI tooling to accelerate development, experience running AI infrastructure.

Responsibilities

• Design, build, and operate the on-premises Kubernetes platform and the underlying Linux VM fabric.
• Design the hypervisor architecture, host networking topology, and storage backing.
• Design and maintain distributed shared storage such as Ceph.
• Build VM templating and golden-image pipelines.
• Automate the VM lifecycle using infrastructure as code.
• Own virtual networking within the fabric and its handoff to the Kubernetes CNI layer.
• Manage the full lifecycle of on-premises Kubernetes clusters, including bootstrapping, upgrades, scaling, and decommissioning.
• Configure CNI, network policy enforcement, and on-premises load balancing.
• Build GitOps-based delivery with ArgoCD or Flux.
• Harden hosts and clusters against CIS benchmarks and manage secrets.
• Plan and execute upgrades with minimal workload disruption.
• Troubleshoot incidents across the full stack, from pods and Kubernetes components to the underlying VM and hypervisor.
• Share an on-call rotation for platform-level incidents.
• Coordinate with datacentre and network teams on physical host provisioning.

Skills

Kubernetes

Linux

Networking

Storage

Terraform

Ansible

CI/CD

GitOps

Observability

Security hardening

Tools

KVM/libvirt

Ceph

Prometheus/Grafana

ELK/Loki

ArgoCD

Flux

Job description

Referment is seeking an experienced on-prem platform engineer to design, build, and operate the Kubernetes platform and VM fabric in a high-stakes, low-latency trading environment.

The role covers full lifecycle management of on-prem Kubernetes clusters, including bootstrapping, upgrades, and scale, with strong emphasis on storage, networking, and observability. Collaboration with data center and network teams is essential.