Senior Site Reliability Engineer (f/m/d)

Location: Europe (Time zone: CET ± 4h) or on-site/hybrid in Hamburg, Germany. We are a remote-first company.

About Us

At Kubermatic, we believe that businesses should focus on their core purpose: writing groundbreaking applications, not operations. In line with our commitment to make Kubernetes as easy as possible, we help IT teams worldwide to fully automate their Kubernetes and cloud native operations across multi-cloud, edge, and on-prem.

As one of the top corporate contributors to the Kubernetes project, we develop enterprise-grade software solutions and provide professional services and support to safely navigate and accelerate your cloud native transformation. Our open-source Kubermatic Kubernetes Platform makes it easy to operate thousands of Kubernetes clusters on any infrastructure.

Role Summary

As a Site Reliability Engineer (SRE) with a focus on Kubernetes, you'll help ensure the reliability, availability, performance, and security of Kubernetes-based infrastructure and cloud-native applications. You'll work closely with our engineering and customer delivery teams to build, operate, and continuously improve infrastructure and services across different environments.

Your work will involve troubleshooting complex issues, automating operational tasks, and implementing best practices for monitoring, incident response, and system reliability. You'll help us build resilient infrastructure, improve operational efficiency, and deliver a dependable experience for our customers.

We're looking for someone who enjoys solving challenging infrastructure problems, takes ownership of reliability, and is passionate about Kubernetes, Linux, and automation.

What Will You Be Doing?

• Collaborate with engineering and customer delivery teams to design, build, and maintain reliable Kubernetes-based infrastructure.

• Operate and maintain production KKP seed and master clusters across AWS, GCP, Azure, vSphere, and Hetzner, including version upgrades, migration planning, and rollback procedures

• Provision and manage QA, staging, and demo environments for product teams, ensuring they stay current with release candidates and upgrade paths

• Perform credential and certificate lifecycle management across multi-tenant environments, including rotating cloud provider secrets (Azure, AWS, vSphere), managing Vault policies, and operating cert-manager with Let's Encrypt

• Develop and maintain automation tools and scripts to streamline infrastructure provisioning, configuration, and operational workflows.

• Monitor system health and performance, analyse trends, and identify opportunities to improve reliability, scalability, and efficiency.

• Implement and maintain best practices for observability, alerting, incident response, and service reliability.

• Support KubeVirt operations, including virtual machine provisioning, operator lifecycle, cert rotation for KubeVirt and CDI components, and network connectivity between seed clusters and KubeVirt workloads

• Write and maintain Infrastructure as Code using Terraform and Helm, manage Terraform state across customer environments, and detect and resolve configuration drift

• Collaborate with engineering teams to identify recurring problems, improve operational processes, and prevent incidents from happening again.

• Build and maintain observability with Prometheus, Grafana, and the KKP Monitoring, Logging, and Alerting (MLA) stack so that issues surface before customers notice them.

• Stay up to date with developments in Kubernetes, Linux, cloud-native technologies, and the broader open-source ecosystem.

• Support engineering and product teams by investigating customer-reported issues, tracing problems through the KKP codebase, and providing technically grounded responses

• Contribute to open-source projects and upstream initiatives where appropriate.

What You Should Bring

• 6+ years of Professional experience as a Site Reliability Engineer, DevOps Engineer, Platform Engineer, Systems Engineer, or in a similar infrastructure-focused role.

• Deep understanding of Kubernetes internals, including the API server, etcd, kubelet, CSI, CNI, CRI, admission webhooks, and certificate management

• Strong experience with at least two major cloud providers (AWS, GCP, Azure) and their managed services

• Production experience with Infrastructure as Code using Terraform and Helm

• Solid Linux systems administration covering networking, storage, systemd, and debugging with tools like strace, tcpdump, and iptables

• Comfort reading and writing Go. You do not need to be a Go developer, but you should be able to read controller-runtime reconcilers, trace code paths, and write small tools

• Experience maintaining and improving CI/CD infrastructure. Our pipelines run on Prow and GitHub Actions across all Kubermatic products, so you should be comfortable owning that kind of system end to end

• Experience with secrets management (Vault, External Secrets Operator) and PKI/TLS operations

• Experience building and maintaining observability stacks, including monitoring, logging, and alerting with tools such as Prometheus, Grafana, and Loki

Nice to have

• Experience with bare-metal Kubernetes, including PXE boot, IPAM, and hardware lifecycle management

• Familiarity with KubeVirt and running virtual machines on Kubernetes

• Experience with Ceph or other distributed storage systems

• Familiarity with network overlays such as Cilium, Calico, or Kube-OVN

• Contributions to CNCF or open-source Kubernetes projects

What We Offer

• Competitive salary.

• B2B contracts available, with paid time off annually plus local bank holidays.

• Remote-first: work from anywhere in Europe (CET ± 4h).

• A dynamic yet laid-back team environment.

• Regular hackathons and company offsites.

• Best-in-class development tools of your choice.

• Full support for training and certifications (CKA, Linux Foundation, etc.) and conference attendance.

• Speaker support: we'll back you if you want to present at events.

• Active community involvement: enjoy our meetups and our flagship community conference, ContainerDays.

Process

1. Screening call with the recruiter

2. 90-min technical interview with the engineering team. 30 mins of technical Q&A and 60 mins of Live cluster debugging

3. 60-min meeting with Moath.

4. 60-min meeting with Sebastian Scheele (Technical Co-founder and CEO)