Principal Site Reliability Engineer, Reading

Principal Site Reliability Engineer Location: Reading- Hybrid working (2-3 days onsite) Salary:£95,000 (plus bonus) Clearance: Active SC clearance required This role is a senior technical role focused on ensuring large-scale software systems and platforms are reliable, scalable, and performant. Principal SREs sit at the top of the engineering ladder, combining deep software and infrastructure expertise to build the systems, tooling, and practices that keep critical platforms running at scale. They are hands-on engineers who also lead technically, setting standards and mentoring others rather than managing peopleWe have an exciting opportunity for a Principal Site Reliability Engineer to join a major UK critical infrastructure programme delivering large-scale cloud-native transformation at enterprise scale. In this role, you'll be embedded within a high-performing Cloud Pod as a senior technical contributor, working alongside experienced engineers to build, maintain, and improve platform reliability across complex Kubernetes and OpenShift environments.You'll work within a modern cloud-native environment leveraging Kubernetes, OpenShift, GitOps, service mesh, observability tooling, and automation-first engineering practices. This is a technically hands-on role where you'll take a leading voice in platform stability, mentor others, and play a key part in shaping SRE best practices across the programme.Skills Required Strong hands-on expertise in Kubernetes and OpenShift (non-negotiable) Experience working in complex multi-cloud or hybrid environments Proficiency in service mesh technologies such as Istio Experience with observability stacks including Prometheus, Grafana, Loki, and Tempo Strong Infrastructure as Code experience using Kustomize or Helm, with scripting skills in Bash and/or PythonCI/CD pipeline experience using GitOps principles such as Tekton, ArgoCD, or FluxCD Strong automation mindset with a focus on consistency and reliability Desirable Familiarity with Red Hat ACM/ACS and networking tools such as Submariner Hands-on experience with EDB Postgres for enterprise-grade databasesCKA or CKS certification Experience mentoring junior engineers and promoting best practices across teams In Return You'll Receive: Long-term programme stability and clear progression opportunities within a growing cloud and platform engineering practice Access to industry certifications, thinktanks, hackathons and over 250,000 learning resourcesThe chance to develop your SRE capabilities in a modern enterprise platform environment supporting Critical National Infrastructure Join one of the World's Most Ethical Companies, recognised by Ethisphere for 13 consecutive years RSG Plc is acting as an Employment Agency in relation to this vacancy.TPBN1_UKTJ