Senior Systems Administrator

About the role

We are seeking a Senior Systems Administrator to join a major infrastructure security uplift program. The role involves working across both Windows and Linux server environments to deliver security‑focused projects for an enterprise client in Sydney.

Key responsibilities

• Build and configure Windows and Linux servers according to documented standards.
• Support Essential Eight maturity and broader cyber‑security uplift initiatives.
• Deploy and manage Microsoft Defender for Endpoint across server platforms, including Linux.
• Roll out application control and server hardening solutions on both operating systems.
• Collaborate with infrastructure, security, and project teams to improve server security posture.
• Provide operational support, troubleshooting, and platform optimisation.

Required profile

• Extensive systems administration experience on Windows and Linux.
• Proven track record delivering security uplift or Essential Eight programs.
• Hands‑on experience with Microsoft Defender for Endpoint.
• Strong troubleshooting ability and a security‑first mindset.
• Excellent communication and stakeholder engagement skills.

Required skills

• Windows Server administration
• Linux server administration
• Microsoft Defender for Endpoint
• Application control technologies
• Endpoint security tooling
• Server hardening and configuration
• Essential Eight maturity framework