Senior Site Reliability Engineer (SRE)

Role: Senior Site Reliability Engineer (SRE) – Kubernetes / OKD Department: Cloud Location: Remote -UK (possible paid occasional travel to TIG Secure site or customer locations as required) Job Type: Full-time, Permanent Salary: Competitive + benefits + package Security Clearance Requirements Please note that holding a current Security Clearance is not essential at the time of application, but eligibility is required. This role requires the successful candidate to be eligible for Security Check (SC) clearance . To meet this requirement, applicants must: Have the right to work in the UK Have lived in the UK continuously for the past 5 years Not have spent more than 6 months outside the UK in total during that period Be willing to undergo security vetting as part of the onboarding process About Us Come and be part of The Investigo Group (TIG) , a dynamic coalition of technology businesses specialising in Platform, Software, Data, AI and secure digital solutions. Our group is made up of several specialist brands, including: Voixtel — secure communications and voice platforms for regulated and critical environments. IIS — secure internet access for public and private sector organisations. Vestigo Consulting — specialist consultancy, training and sector-specific expertise. Collaboraite — our Data and AI capability, focused on secure, user-centred data solutions. Across TIG, we build secure, user-focused products and services for organisations operating in complex, regulated and mission-critical environments. We combine deep technical knowledge with advanced data, platform and engineering capability to solve real-world customer challenges. We are also committed to creating an inclusive environment where people from all backgrounds are welcomed, supported and empowered to do their best work. About You You are an experienced SRE, Platform Engineer, Cloud Engineer or Kubernetes Engineer with strong hands-on experience operating production Kubernetes environments. You do not just deploy into Kubernetes — you understand what it takes to run it properly in production. You are comfortable working across Linux, Kubernetes, infrastructure as code, GitOps, CI/CD, observability, identity and secure platform operations. You treat infrastructure as a product. You care about measurable reliability, clean automation, useful observability, well-maintained runbooks and platforms that other engineers can genuinely rely on. You are calm and methodical during incidents, able to lead blameless post-mortems, and focused on turning operational issues into long-term improvements. You are likely to have worked in a regulated, secure, government, defence, financial services, telecoms, managed services, consultancy or cloud-native environment. Most importantly, you have operated Kubernetes at depth and understand the realities of production ownership. This role is suited to a senior individual contributor who can mentor others, influence engineering practice and act as a technical authority without needing formal line management responsibility. Soft Skills Calm and structured under incident pressure, with the discipline to debug methodically rather than thrash. Strong written communication, runbooks, post-mortems, design notes, and customer-facing reports need to be clear and durable. Collaborative working style, particularly across networking, security, and application engineering boundaries. Comfortable holding a blameless line in post-mortems while still driving systemic fixes. Able to influence engineering practice through evidence and example rather than positional authority. Mentoring instinct, willing to lift the capability of those around them. About the Role We are looking for a Senior Site Reliability Engineer — Kubernetes / OKD to help own, operate, harden and mature our production Kubernetes estate. TIG operates production OKD / Kubernetes platforms that support services for UK government and regulated customers. These platforms are foundational to our service delivery and to the products other engineering teams build on top of them. Reliability, security and operational maturity are therefore critical to how we deliver for customers. This is a hands-on senior engineering role, not a ticket-handling position. You will work across the full stack, from bare metal and virtualisation through to Kubernetes control plane operations, ingress, observability, identity, CI/CD and the developer platform layered on top. You will play a key role in improving the operational maturity of our platform estate, supporting a key migration, strengthening GitOps and CI/CD practices, and ensuring our platforms remain reliable, secure, measurable and supportable. You will work closely with platform, application, AI, networking, security, QA and architecture teams to build reliable foundations that enable engineering teams to deliver safely and at pace. What the role offers you Direct ownership of platforms that ship into government-regulated environments. Modern self-hosted toolchain, including OKD / Kubernetes and an on-premises AI platform running on NVIDIA DGX hardware. A small, senior engineering team with minimal bureaucracy and CTO-led technical decisions. Genuine remote-first working, with travel only where it adds value. About the Team Platform Engineering is responsible for the foundational platforms on which TIG's services run, including our OKD / Kubernetes estate, our internal developer platform, and the supporting cloud, networking, and security infrastructure. The team works across UK government and regulated commercial engagements and operates within accredited environments. Key Responsibilities Operate, harden and extend production OpenShift / OKD / Kubernetes clusters across on-premises and hybrid environments. Supporting migrations, helping modernise the underlying compute and infrastructure layer. Own CI/CD processes across the full lifecycle of platform and application components. Own and mature GitOps deployment practices, particularly using tools such as Argo CD. Support cloud-native application delivery using tools such as Helm and Kustomize. Maintain and improve core platform services including Keycloak, ingress, observability, certificate management, service mesh and container registry capabilities. Build and operate observability across logs, metrics, traces, alerting, SLOs and error budgets. Improve platform hardening in line with secure and regulated environment requirements. Automate repeatable operational tasks using tools such as Ansible, Terraform, Helm, Kustomize, Go, Python or similar. Lead incident response activity, support blameless post-mortems and drive systemic fixes. Partner with networking and security teams on platform integration, segmentation, load balancing and accreditation evidence. Create and maintain clear technical documentation, runbooks, design notes and operational guidance. Mentor engineers and act as a senior technical authority across cloud and Kubernetes operations. Participate in an on-call rota, with appropriate compensation. Success in This Role Looks Like A more reliable, secure and measurable production OKD / Kubernetes estate. Clear SLOs, error budgets and reliability trend data that engineering teams actively use. A mature GitOps approach covering platform and application components, including rollback and drift detection. Improved CI/CD practices that help teams move at pace while bringing security, QA and compliance earlier into the lifecycle. Hardened, well-documented and supportable core platform services. Observability that reduces noise and supports better engineering decisions. Stronger incident response, clearer runbooks and post-mortems that lead to real operational improvements. Recognition as a technical authority for Kubernetes, cloud and platform operations across TIG. Essential Experience & Skills Strong experience running production Kubernetes environments, not just consuming or deploying into them. Strong Linux fundamentals, including systems, networking, storage and performance troubleshooting. Experience with Kubernetes distributions such as OKD, OpenShift, vanilla Kubernetes, Rancher, EKS, AKS or GKE. Infrastructure as code experience, including Ansible plus Terraform or equivalent. Experience with Helm, Kustomize or similar cloud-native deployment tooling. GitOps and CI/CD experience managing full application and component lifecycles, using tools such as Argo CD, Flux, GitHub Actions or similar. Observability across logs, metrics and traces, using tools such as Prometheus, Grafana, Elastic Stack, LGTM and OpenTelemetry. Experience with identity and access technologies such as OIDC, SAML, SCIM or Keycloak. Experience with virtualisation or infrastructure platforms such as KVM, libvirt or VMware. Scripting or tooling experience using Go, Python, shell scripting or similar. Strong troubleshooting, problem-solving and analytical skills. Experience working in secure, regulated or enterprise-scale environments. Strong written and verbal communication skills, with the ability to produce clear documentation, runbooks, post-mortems and technical guidance. Eligibility to hold UK SC clearance. Desirable (Not Essential) Specific OpenShift or OKD experience, including operators, MachineConfig or SCCs. Service mesh experience such as Istio or Linkerd. Policy engine experience such as OPA, Gatekeeper or Kyverno. Software supply chain security experience, including SBOMs, image signing, admission control or tools such as Sigstore. Storage experience such as Ceph, Longhorn, OpenShift Data Foundation or equivalent. Networking experience including BGP, VXLAN, Palo Alto or Juniper technologies. AI, ML or GPU-enabled platform operations. CKA, CKAD, CKS, Red Hat certifications or equivalent. Active or recent UK SC clearance. Recognised open-source contributions to the Kubernetes ecosystem. Private Medical Health Cash Plan 4x Life Assurance Inclusive Culture : Enjoy an inclusive culture and environment. Holiday : Generous holiday allowance. Learning : Access to continuous learning and development opportunities. Bonus Potential : Bonus potential based on performance and business-related factors. Discounts : Discounts on a wide range of products and services. Pension : Pension scheme contributions. EV Car Scheme Regular Pay Reviews More Benefits : Explore additional benefits on our career site. Equal Opportunities Here at TIG we are committed to equal opportunities and value diversity, equity and inclusion at our company. We do not discriminate based on race, religion, colour, national origin, sex, gender, gender expression, sexual orientation, age, marital status, veteran status, or disability status. As a Group, we seek to ensure that individuals with disabilities receive reasonable accommodation throughout the hiring process and ultimately within the job itself. Please contact us to request any accommodations.