Senior System Administrator – Critical IT Infrastructure

About the role

We are seeking a Senior System Administrator to maintain and modernize a highly secure, technically advanced IT environment. You will join a multidisciplinary team responsible for reliable server operations, virtualization platforms, and core infrastructure services.

Key responsibilities

• Administer Windows and Linux server environments.
• Manage Active Directory, Group Policy Objects, DNS, DHCP, and identity services.
• Monitor and optimise VMware, Proxmox, and Hyper‑V virtualization platforms.
• Ensure infrastructure security, patch management, backups and business continuity.
• Support infrastructure modernisation and scalable architecture design.
• Automate tasks using PowerShell, Bash, Python or similar scripting tools.
• Troubleshoot complex system issues and collaborate with network and security teams.
• Maintain technical documentation and participate in migration projects.

Required profile

• Minimum 7 years of Windows and Linux system administration experience.
• Strong expertise in virtualization, storage and infrastructure security.
• Proven experience with large‑scale Active Directory environments.
• Solid scripting skills (PowerShell, Bash, Python).
• Understanding of networking, security and identity management concepts.
• Bachelor’s or Master’s degree in IT or equivalent experience.
• Analytical, proactive, reliable and able to work under pressure.
• Native/fluent Dutch or French and active technical English.

Required skills

• Windows Server
• Linux
• Active Directory
• Group Policy Objects
• DNS & DHCP
• VMware
• Proxmox
• Hyper‑V
• PowerShell
• Bash
• Python
• Azure (plus)
• AWS (plus)
• Virtualisation
• Storage management
• Infrastructure security
• Patch management
• Backup & business continuity
• Scripting automation
• Networking concepts
• Identity management

What we offer

• Fixed‑term contract until June 2026, renewable.
• Hybrid work model with up to two remote days per week.
• TOP SECRET security clearance required.
• Opportunity to work on critical, high‑impact infrastructure projects.