Senior DevOps Engineer

Virtualisation & Compute

• Operate, maintain, and improve our Proxmox VE virtualisation estate across all data centre sites
• Own capacity planning, host lifecycle, and hypervisor upgrades with minimal service impact
• Ensure the compute layer meets the availability demands of real-time communications workloads

Storage

• Own storage architecture, performance, and integrity across the estate, including Ceph and block storage
• Own backup and recovery: replication, retention, and restore procedures that are tested regularly, not assumed to work
• Plan and execute storage growth ahead of demand from both platforms

Container Orchestration

• Run container orchestration in production day to day
• Lead our continued move deeper into Kubernetes: cluster design, workload migration, and operational standards
• Support development teams on both products with reliable build, deployment, and runtime environments

Automation & Infrastructure as Code

• Build and maintain infrastructure as code with Ansible and Terraform - the estate should be reproducible from code, not folklore
• Automate routine operations, patching, and provisioning across both platforms
• Drive configuration consistency across sites and environments

Monitoring, Reliability & Incident Response

• Own monitoring and alerting for the platform layer, keeping signal high and noise low
• Act as senior escalation for platform-level incidents on either product, including out-of-hours escalation on a planned basis
• Contribute to post-incident reviews with clear root cause analysis and corrective actions
• Participate in disaster recovery and failover testing across the estate

Documentation & Collaboration

• Maintain accurate runbooks, diagrams, and SOPs for the platform layer
• Put forward architecture proposals and business cases to the Infrastructure Manager for review and approval
• Collaborate with the network, service, and development teams to align platform work with product needs on both circle.cloud and Olatti
• Get hands-on in the data centre when the work calls for it

• Five or more years in DevOps or infrastructure roles, ideally in SaaS, telecoms, or other infrastructure-heavy environments
• Production Kubernetes experience - designing, running, and debugging real workloads. This is the single biggest win.
• Strong Proxmox experience, especially Ceph and block storage - a close second
• Solid infrastructure-as-code habits with Ansible, Terraform, or similar
• Linux administration at scale, bare metal and virtual
• Experience operating production-critical environments where uptime is non-negotiable
• Strong documentation habits in production environments
• UK-based, within reach of Southampton for office days and data centre visits

Desirable Experience

• Prior experience in a telecoms, VoIP, or UC service provider environment
• Understanding of real-time media workloads (SIP, RTP) and what they demand from infrastructure
• Database operations experience (PostgreSQL or similar) in production
• Networking fundamentals sufficient to work effectively alongside a carrier-grade network team
• CI/CD pipeline design and developer platform experience

Working Style

• Hands-on, methodical, and reliable in live production environments
• Calm, decisive, and accountable under pressure
• Strong ownership mindset - you see problems through to resolution and write down what you learned
• Collaborative with network, service, and development teams
• Comfortable owning a domain end to end in a small senior team, * Kubernetes: 2 years (required)
• CEPH: 2 years (required)
• Proxmox: 2 years (required)

Pulled from the full job description

• Referral programme
• Annual leave
• Employee discount
• Company pension
• Discounted or free food
• Private medical insurance
• Cycle to work scheme, Working Hours 08:30 to 17:30. This is a senior role with autonomy and accountability. We value outcomes, ownership, and effective time management over clock-watching. Out-of-hours support is required on a planned and escalation basis.

Holiday

• 21 days annual leave
• Birthday day off
• Bank holidays, * Company events
• Company pension
• Office canteen & games zone
• Cycle to work scheme
• Discounted or free food
• Employee discount
• Health & wellbeing programme
• On-site parking
• Private medical insurance
• Referral programme
• Work from home (as part of agreed hybrid pattern)

Job Type: Full-time

Pay: £55,000.00-£75,000.00 per year

Benefits:

• Canteen
• Company pension
• Cycle to work scheme
• On-site parking
• Private medical insurance
• Work from home

Circle Cloud Communications Ltd is a telecommunications provider operating carrier-grade, on-prem infrastructure. We maintain our own IP space via RIPE, run our own ASN, and deliver business-critical unified communications and telephony services. We’re also building Olatti, our next-generation business phone system, which runs on the same infrastructure estate.

The Senior DevOps Engineer owns the platform layer of that estate: virtualisation, storage, container orchestration, and the automation that holds it all together. You’ll run the infrastructure beneath two products - the established circle.cloud telephony platform and the new Olatti platform - on one shared estate of our own hardware in UK data centres. Keeping data on infrastructure we control is a deliberate choice, and this role is central to it.

This is a hands-on senior engineering role. You’ll work alongside the Infrastructure Manager, who owns the network layer, and you’ll be the senior authority on everything that runs on top of it: hypervisors, storage clusters, Kubernetes, deployment pipelines, and the monitoring that tells us about problems before customers do.

About the Environment

• On-prem, bare-metal infrastructure across four interconnected sites
• Fibre ring topology with geographic resilience
• Minimal public cloud usage
• Business-critical production telecoms services with real-world uptime demands
• Two product platforms - circle.cloud and Olatti - running on one shared estate
• A small, capable team where senior engineers own their domain end to end