System Administrator (Defence & Security)
Reaktor's Defence & Security unit in Helsinki is hiring a System Administrator for its internal IT team. Day to day they build and maintain secure internal IT systems, develop automation, handle networking, security, and troubleshooting, and support consultants on security-critical projects using Linux, scripting, and automation tooling.
- Compensation
- Not disclosed
- Location
- Helsinki
- Work setup
- Onsite
- Seniority
- Not specified
- Employment
- Not specified
- Experience
- 5+ years
- Category
- Devops
- Posted
Skills
Must have
- Minimum of 5 years of relevant experience in system administration or IT infrastructure roles
- Strong knowledge of Linux (Ubuntu, 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 onsite, with limited hybrid working possibilities
- Finnish citizenship due to client and security regulations
- Must successfully complete a security clearance process
Nice to have
- Experience with Ansible or similar automation tools
- Familiarity with Windows and macOS desktop administration
- Coding experience in TypeScript, Python, or Go
Full description
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.
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.
What you’ll be doing
- 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.
To thrive in this position, you’ll need:
- 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.
This position requires Finnish citizenship due to client and security regulations. The selected candidate must successfully complete a security clearance process.