System Administrator - SiteOps

Zellerfeld is revolutionising the footwear industry with the world’s first 3D-printing technology for fully customizable shoes. Our goal is simple: printed shoes on every foot. We’re a passionate team of engineers, designers, and innovators, questioning the status quo and disrupting traditional manufacturing processes. Backed by founders, influencers, and celebrities who believe in our vision, we’re committed to making a lasting, positive impact—not just on the footwear industry, but on the world.

Your Mission

You’ll be the cornerstone of our technical infrastructure — the person who keeps everything running, secure, and ready to scale. As our On-Premises DevOps Engineer, you’ll bridge development and operations, automating workflows, hardening our systems, and ensuring the reliability our production environment depends on. From network security to CI/CD pipelines, you’ll own the full infrastructure stack and play a critical role in building the factory of tomorrow.

What You’ll Do

• Design, implement, and maintain our network infrastructure, including firewall configuration and segmentation
• Run and evolve our virtualization and containerization platforms (Proxmox, Docker, Docker Swarm)
• Build and maintain CI/CD pipelines that deliver software reliably to production
• Apply Infrastructure as Code practices so our environment is reproducible, auditable, and recoverable
• Administer Linux servers — security, performance, availability, and the unglamorous work that keeps them healthy
• Configure reverse proxies, manage NAS systems, and own the storage and traffic layers
• Implement logging, monitoring, and alerting so we know about problems before our colleagues do
• Provide infrastructure support across all tiers — you're the person teams come to when something breaks
• Collaborate with developers to make systems more reliable, observable, and easier to operate
• Document the stack so it's not all in one person's head

Your profile

• Strong Linux server administration (Ubuntu in our case), including security hardening
• Real network experience: Fortinet firewalls, TCP/IP, VLANs, switching (we use AOS-CX)
• Virtualization and containers: Proxmox, Docker, Docker Swarm
• Infrastructure as Code with Ansible and/or Terraform
• CI/CD pipeline experience, especially GitLab CI/CD and Github Actions
• Comfortable with reverse proxy configuration (Nginx, Traefik)
• Monitoring and observability across the stack (Zabbix, Grafana, Prometheus, Elastic Stack)
• The temperament for on-prem work — methodical, security-minded, and calm when production hardware is involved
• As a company specializing in both hardware and software, we value close collaboration within our team. Therefore, we are seeking candidates who can join us at our office in Hamburg

Nice To Have

• NAS administration, particularly TrueNAS
• Experience supporting production or manufacturing environments
• Background bridging IT and OT (operational technology) in a hardware-adjacent setting