Senior System Administrator Job ID: JP054241

Senior System Administrator We are looking for a Senior System Administrator to support and modernize critical IT infrastructure within a highly secure and technically advanced environment. You will work in a multidisciplinary team responsible for maintaining reliable server environments, virtualization platforms, and infrastructure services while contributing to system evolution and operational excellence. Responsibilities Administer and maintain Windows and Linux server environments Manage Active Directory, GPO, DNS, DHCP, and identity services Monitor and optimize virtualization platforms such as VMware, Proxmox, and Hyper-V Ensure infrastructure security, patch management, backups, and business continuity Support infrastructure modernization and scalable system architecture design Automate operational tasks using PowerShell, Bash, Python, or similar scripting tools Troubleshoot and resolve complex infrastructure and system issues Collaborate with infrastructure, network, and security teams Maintain technical documentation and operational procedures Participate in infrastructure migrations and continuous improvement initiatives Requirements Minimum 7 years of experience in Windows and Linux system administration Strong expertise in virtualization, storage, and infrastructure security Proven experience with Active Directory and large-scale infrastructure environments Solid scripting skills (PowerShell, Bash, Python, or equivalent) Understanding of networking, security, and identity management concepts Experience with Azure or AWS is considered a plus Bachelor's or Master's degree in IT or equivalent experience Soft Skills Analytical and solution-oriented mindset Proactive, autonomous, and reliable Strong communication and documentation skills Able to work under pressure in critical environments Team player with strong problem-solving abilities Languages Dutch or French: native/fluent level Good understanding of the second national language English: active technical knowledge Location Hybrid role based in Brussels Up to 2 remote workdays per week Additional Information Initial contract until end of June 2026 Second contract until end of 2026, renewable A TOP SECRET security clearance is required for this position