Linux System Administrator (Wrocław, hybrid)
About the role.
We're hiring a mid-level Linux System Administrator in Wrocław to run our on-premise infrastructure: our own physical servers in Stockholm. You'll keep the servers, the operating system, and our core services healthy and secure, work alongside our developers, and travel to Stockholm several times a year to install and replace hardware.
- Seniority: Mid (3+ years)
- Location: Wrocław, Poland. Hybrid: remote + office in Wrocław, flexible office days. We’re looking for someone based in or near Wrocław (or willing to relocate).
- Contract: B2B with DomainCrawler AB, Sweden
- Rate: 3,000–3,500 EUR net per month (B2B invoice)
- Travel: Stockholm, several times a year , costs covered
DomainCrawler is a Swedish company that provides structured domain name data to businesses. Our database covers more than 1.4 billion registered and unregistered domains, with a wide range of data on each: DNS, SSL certificates, ownership, hosting, technologies and more. Domain registries and registrars, brand protection agencies and
OSINT investigators use it to fight counterfeiting, uncover threats and research markets.
Responsibilities:
- Monitor the health of the servers and services, and fix issues when they come up.
- Patch and update Debian, including major release upgrades.
- Keep our self-hosted CI/CD and source control tools running: upgrades, backups runners and agents, plugins. Developers own the pipelines.
- Keep the runtime environment for our services working: OS packages, systemd and logs.
- Run backups, test restores regularly, and keep the disaster recovery plan up to date.
- Manage the network: switches, firewalls, VPN.
- Handle security: hardening, vulnerability scanning, and access management (SSH keys, sudo, onboarding and offboarding).
- Extend our Prometheus and Grafana monitoring, and bring all servers under configuration management.
- Look after hardware: catch failing disks, memory and other components early (SMART, ECC and kernel errors), firmware and BMC updates, RAID health.
- Coordinate on-site remote-hands support between visits.
- Travel to Stockholm several times a year to install and replace hardware.
- Keep documentation up to date: hardware inventory , network diagrams and runbooks.
- Work with developers on what they need from the infrastructure, and contribute to capacity planning.
Must-have: - 3+ years administering Linux servers in production, with hands-on Debian or Ubuntu experience: apt, systemd, unattended-upgrades and major release upgrades.
- Hands-on work with physical servers: racking, cabling, replacing components, IPMI or iDRAC, and both hardware and software RAID.
- Networking fundamentals: TCP/IP, VLANs, routing, DNS, firewalls (nftables or iptables).
- Configuring managed switches from at least one major vendor.
- Configuration management with Ansible or a similar tool.
- Prometheus and Graf ana: exporters, dashboards and alerting rules.
- Designing backups and testing restores.
- Security practice: hardening, patch management, access management.
- Administering self-hosted CI/CD tools such as GitLab or Jenkins.
- English good enough for documentation and daily communication.
- Willingness to travel to Stockholm several times a year and to do physical work such as lifting and racking servers.
Nice-to-have: - Enterprise network equipment such as Juniper or Cisco.
- OpenVPN, WireGuard or another VPN technology.
- Centralized logging (ELK, Loki or Graylog).
What we offer: - 3,000–3,500 EUR per month on a B2B contract with DomainCrawler AB, Sweden, paid in EUR.
- 24 paid days off per year.
- Hybrid work with flexible office days at our Wrocław office.
- Travel to Stockholm several times a year, with travel costs covered.