Platform Engineer

You'll join at a moment when we're moving our retail analytics platform from monthly bundled releases to continuous per-service deployment on Kubernetes. You'll be hands-on with that migration in your first few months and then stay on long-term as a core member of the team that owns and evolves the platform. It's a clear path into senior platform engineering for someone who has shipped production Kubernetes work and wants to grow their craft on a platform used by hundreds of engineers., * Build and maintain the platform primitives that enable service teams to deploy independently, including ArgoCD application manifests, GitOps repository lifecycles, reusable Helm chart templates, and External Secrets Operator configuration.

• Pair with engineers across product and data teams as they onboard onto the new platform, addressing repeated questions at the template layer to prevent recurring issues.
• Contribute to platform design discussions and help shape the paved road that engineers across dunnhumby build on.
• Author and maintain reusable GitLab CI pipeline templates covering build, test, publish, deploy, and post-deploy stages.
• Work with service teams to migrate pipelines onto the platform standard and retire bespoke per-service deployment scripts.
• Continuously improve build times, pipeline reliability, and developer feedback loops.
• Respond to platform alerts during working hours, triaging ArgoCD sync failures, secret synchronisation errors, and flaky pipelines.
• Join the Application Platform on-call rotation once ramped up (typically after the first few months).
• Instrument platform tooling with structured logging and dashboards to improve visibility without manual investigation.
• Write unit and integration tests to meet SonarQube coverage requirements and create smoke tests for deployment workflows - no green CI, no merge.
• Keep migration playbooks, ArgoCD setup guides, and per-service pipeline documentation accurate and up to date.
• Share learnings with the squad through regular knowledge-sharing sessions.

• Strong professional software or platform engineering experience, shipping code or infrastructure to production within a team environment
• Hands-on Kubernetes experience on GKE, AKS, or EKS, with confidence using Deployments, Services, Ingress, ConfigMaps, Secrets, and RBAC
• Helm experience, including writing or substantially modifying charts, with a solid understanding of values files, templates, hooks, and chart dependencies
• Experience with GitLab CI or a comparable CI tool (e.g. GitHub Actions, Azure DevOps, Jenkins, CircleCI), having built or meaningfully modified pipelines rather than just used them
• Production experience with Python or Go, with the ability to discuss real code from professional work
• Confidence working with Linux, Bash, Docker, and standard Unix tooling
• Strong Git practices within a team environment, including branching strategies, PR/MR workflows, review feedback, and merge conflict resolution
• A proven track record of shipping to production in a professional team setting (not solely prototype or personal projects)
• Exposure to ArgoCD, Flux, or another GitOps tool is a strong plus
• Experience with External Secrets Operator, Vault, or similar secret-sync patterns is beneficial
• Familiarity with Terraform, multi-cloud environments (GCP and Azure), observability tooling (e.g. New Relic, Datadog, Prometheus, Grafana), or contract testing with Pact would be valuable