On-Site System Administrator, Defence & Security

Reaktor; Helsinki; Hybrid; EUR 60,000 - 75,000; Full time

Benefits offered by this job

Top-spec computer

Phone & internet covered

Lunch benefit

Recreational benefit

Commute & bicycle benefits

Occupational healthcare

Family support

Insurance package

Open source Juice program

Job summary

Reaktor's Defence & Security Unit in Helsinki is seeking a System Administrator to join our internal IT team on-site. You’ll maintain secure, automated environments that support world-class development work and collaborate with DefSec consultants, developers, and stakeholders.

We value a proactive mindset, strong Linux and networking knowledge, scripting experience, and fluency in Finnish and English. Due to security regulations, Finnish citizenship and security clearance are 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.
• This position requires Finnish citizenship due to client and security regulations.

Responsibilities

• Systems Installation & Maintenance – Build and maintain internal IT systems that enable high-performing development work.
• Automation & Infrastructure Development – Maintain and improve automation for system maintenance with state-of-the-art tooling.
• Security & Stability – Ensuring environments are safe, compliant, and reliable.
• Cross-functional Collaboration – Partner with consultants, developers, and stakeholders to solve complex challenges.
• Support & Troubleshooting – Resolving issues from hardware to networks and automation.
• Documentation & Knowledge Sharing – Document practices and share learnings with the team.
• Continuous Improvement – Evolve internal systems and support long-term infrastructure planning.

Skills

System administration

Linux

Networking & security

Scripting

Communication

Finnish & English

Proactive problem solving

Team collaboration

Tools

Ansible

Windows

macOS administration

Job description

Reaktor's Defence & Security Unit in Helsinki is seeking a System Administrator to join our internal IT team on-site. You’ll maintain secure, automated environments that support world-class development work and collaborate with DefSec consultants, developers, and stakeholders.

We value a proactive mindset, strong Linux and networking knowledge, scripting experience, and fluency in Finnish and English. Due to security regulations, Finnish citizenship and security clearance are required.