Senior System Administrator

About the role

We are looking for a Senior System Administrator to lead the design, deployment and hardening of our Active Directory and server infrastructure. The role combines hands‑on Windows and Linux administration with advanced AD, VMware and security hardening tasks.

Key responsibilities

• Produce a detailed design for a new AD server and build it to the company’s Standard Operating Environment (SOE) with security hardening.
• Promote the AD server into the RBA domain, perform AD join, and apply GPO‑based hardening.
• Execute patching, firmware updates and ensure ongoing system maintenance.
• Monitor system performance, tune resources and troubleshoot issues across Windows and Linux platforms.
• Support testing, validation and production go‑live (ORE) activities, providing sign‑off documentation.
• Follow documented SOPs for server builds and, where required, carry out virtual server migrations.

Required profile

• Extensive experience administering Windows and Linux servers.
• Strong knowledge of Active Directory (join, promote), DNS and domain services.
• Proficiency with VMware environments and virtual server migration.
• Demonstrated ability to build systems to SOE standards and apply security hardening (GPO, off‑domain).
• Experience with patch management, firmware updates and system monitoring.
• Solid troubleshooting and performance‑tuning skills.

Required skills

• Windows Server administration
• Linux system administration
• Active Directory & DNS
• VMware virtualization
• Group Policy Object (GPO) hardening
• Patch management & firmware updates
• System monitoring & performance tuning
• Virtual server migration