System Administrator - SiteOps

• 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

• 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

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

At Zellerfeld, you will find a multidisciplinary team of engineers, SW and HW specialists, entrepreneurs, designers, and students with a common passion. We embrace contrarian thinking, humility, pushing limits, and improving ourselves. We utilize a flat hierarchy, and we want your voice to be heard. We also care about bonding because we want to be a tight-knit community, so be prepared to spend quality time with everyone, including the CEO!

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.