System Administrator

📋 Job Overview

Reaktor’s Defence & Security Unit is looking for a System Administrator to join our internal IT team in Helsinki. Join Reaktor’s DefSec team, where agility, teamwork, and trust drive everything we do. We work on some of the most complex and mission-critical challenges in the industry, helping clients navigate an evolving landscape with cutting-edge solutions.

🏢 About Reaktor

For two decades, we’ve been developing qualities and capabilities for adapting, reacting, and supporting change – building Reaktor to hold up in a fast-paced environment while ensuring the well-being of our people.

🎯 The Role

Are you in your element when maintaining and building secure, automated IT environments that support world-class development work? Do you enjoy solving complex technical challenges hands-on while working alongside dedicated professionals? If so, you might be just the person we’re looking for.

✅ Key Responsibilities

• Systems Installation & Maintenance – Build and maintain DefSec’s internal IT systems that enable high-performing development work.
• Automation & Infrastructure Development – Maintain and improve automation for system maintenance, using state-of-the-art tooling.
• Security & Stability – Ensuring our environments are safe, compliant, and reliable.
• Cross-functional Collaboration – Partner with DefSec consultants, developers, and stakeholders to solve complex and multi-dimensional challenges.
• Support & Troubleshooting – resolving issues from hardware to networks and automation.
• Documentation & Knowledge Sharing – Document practices and systems, and actively share your learnings with the team.
• Continuous Improvement – Help evolve our internal systems and support organization, taking ownership of both day-to-day operations and longer-term infrastructure planning.

📌 Required Qualifications

• Minimum of 5 years of relevant experience in system administration or IT infrastructure roles.
• Strong knowledge of Linux (Fedora, CentOS, or similar).
• Understanding of IP networking, VPNs, and firewalls.
• Familiarity with certificate management and authentication mechanisms.
• Hands-on experience with scripting (Bash, Python, PowerShell, etc.).
• A proactive mindset with a focus on helping others and solving problems.
• Excellent communication skills to interact with both technical and non-technical stakeholders.
• Fluency in both Finnish and English (written & spoken)
• Willingness to work 100% on-site.

⭐ Desirable Experience

• Experience with Ansible or similar automation tools.
• Familiarity with Windows and macOS desktop administration.
• Coding experience in TypeScript, Python, or Go.

🎁 Benefits

The ability to impact how you work. Together with your team, you choose the approach, technologies, and methodologies you think will work best in any given situation. A community with as much support as your heart desires. A team that’s not only experienced but considerate as well – they all want you to succeed. Career development, helping you develop your skills further through guidance and/or courses, and giving you the opportunity to explore your career interests. A sustainable work-life balance and support for your daily life outside of work. Many different hobby clubs, from winter swimming and running to knitting and archery, that bring people together outside of (and sometimes inside) office hours.

🛂 Visa & Eligibility

This position requires Finnish citizenship due to client and security regulations. The selected candidate must successfully complete a security clearance process.