Linux system administrator

You will join the System Administration team and take part in the daily operation of our production infrastructure. This is a hands-on role. You will work with Proxmox and Ceph and help operate a production cluster running around 1000 virtual machines that power our services. A big part of the job is keeping systems stable: monitoring, troubleshooting, upgrades, maintenance windows, and fixing issues before they become incidents. You won’t be “thrown in alone”, but you are expected to take ownership of what you touch, document what you change, and improve things over time. A 24/7 rotating on-call is part of the job., * Help operate and maintain Proxmox production clusters

• Help troubleshoot and maintain Ceph storage (health, capacity, recovery)
• Maintain and troubleshoot Linux virtual machines and the services running on them
• Handle incidents and participate in the on-call rotation (24/7)
• Use SaltStack for configuration management and operational tasks
• Support infrastructure changes, upgrades, and expansions
• Document systems, procedures, and changes

• Solid Linux fundamentals; Linux is your daily operating system
• Basic experience or strong interest in virtualization (Proxmox is a plus)
• Interest in storage systems; experience with Ceph is a plus
• Comfortable working with many services and systems (not just a few servers)
• Basic scripting skills (bash, python, or similar) and an automation mindset
• Familiar with configuration management concepts (SaltStack preferred, or similar tools)
• Able to troubleshoot methodically and communicate clearly
• Comfortable working in production environments where uptime matters
• Comfortable using AI coding tools (e.g., Codex) as part of daily work, * Hands-on experience with Proxmox in production (even small clusters / labs count)
• Hands-on experience with Ceph (even small clusters / labs count)
• Experience with SaltStack (states, pillars, grains, orchestration) or similar tools
• Understanding of monitoring/alerting and incident handling
• Experience with networking basics (VLANs, routing, firewalls)
• Strong documentation habits and clean operational work

Why Mixvoip? Mixvoip offers a unique environment where engineers can truly shape technology - from architecture and automation to security and performance. Here, your ideas matter. We encourage experimentation, support personal growth, and invest in helping every team member become an expert in their craft.

A new way to apply: Join Mixvoip’s success story Join Mixvoip and you won’t just be connecting businesses to high-speed internet, fiber, satellite, phone, or mobile networks - you’ll be connecting people, forging relationships, and making a real difference in our story. So, if you’re prepared to embark on an engaging journey and play a pivotal role in Mixvoip’s saga, here’s an unconventional route to apply We invite you to record a brief video with your smartphone. Share why you’re drawn to this role or pose any questions or doubts you might have. It’s about keeping the conversation open and engaging! Please remember to attach your CV in PDF format too. Instead of a conventional motivational letter, we’d like you to employ an AI of your choice. This not only mirrors our technology-focused approach, but it also allows you to showcase your adaptability to new tools. It’s less about the letter, more about your interaction with AI that we’re keen on.

PS: Want to know who you’ll be journeying with? Meet me, Marcin Rzeczkowski I’ve been with Mixvoip for 14 years, and I still like being close to the technical reality of the company. I do not just want to discuss systems. I want to understand how they behave in production and why. Over the years, I’ve learned that reliability is rarely about one big change. It is usually the result of many small, correct decisions, plus clear thinking during incidents, clean execution, and teamwork that does not fall apart under pressure. I care a lot about collaboration and team spirit, and I also value autonomy. I like people who can take a problem, structure it, and move it forward without waiting to be pushed. Outside of work, I apply the same mindset to fitness and nutrition: discipline, consistency, and measurable progress.