Senior System Administrator – Sydney

About the role

We are looking for a Senior System Administrator to join our IT team in Sydney. The role focuses on designing, building and hardening Active Directory servers and maintaining a robust Windows and Linux infrastructure.

Key responsibilities

• Produce detailed designs and configure AD servers to meet Standard Operating Environment (SOE) standards.
• Promote AD servers into the RBA domain, including AD join, promotion and GPO‑based hardening.
• Apply patching, firmware updates and perform ongoing system maintenance.
• Monitor system performance, tune resources and troubleshoot issues across Windows and Linux platforms.
• Support testing, validation and production deployments (go‑live/ORE) following SOPs.
• Assist with virtual server migrations and VMware environment management (desirable).

Required profile

• Senior‑level experience administering Windows and Linux servers.
• Strong knowledge of Active Directory, DNS and domain services.
• Hands‑on experience with VMware virtualization.
• Proven ability to build systems to SOE standards and apply security hardening.
• Familiarity with patch management, firmware updates and system monitoring.
• Experience following standard operating procedures for server builds and deployments.

Required skills

• Windows Server administration
• Linux system administration
• Active Directory (join, promote, GPO)
• DNS and domain services
• VMware virtualization
• Standard Operating Environment (SOE) implementation
• System hardening (GPO, off‑domain)
• Patching and firmware updates
• System monitoring and performance tuning
• Troubleshooting and incident resolution
• Testing, validation and production deployment processes
• Virtual server migration (desirable)