We are seeking a System Administrator to support a highly secure Government program in Canberra. This role requires a hands-on technical practitioner who is comfortable operating across complex environments and trusted to work autonomously in high-security contexts. You will play a critical role ensuring the stability, integrity and performance of infrastructure supporting nationally significant outcomes. This is an opportunity for a strong generalist who enjoys working across the full stack – from operating systems and infrastructure through to troubleshooting complex technical issues end-to-end. Key responsibilities You will be responsible for the technical operation, sustainment and continuous improvement of secure environments, including: Administration of Linux and Windows systems. Managing servers, applications and databases. Supporting virtualised infrastructure. Troubleshooting issues across OS, infrastructure and application layers. Supporting networking and connectivity components (foundational level). Supporting identity and access management (foundational level). Developing and maintaining automation scripts. Producing and maintaining technical documentation. Ensuring systems operate reliably within secure environments. About you You are a trusted technical professional who can operate confidently in sensitive environments and take ownership of outcomes. You bring: Strong experience as a Systems Administrator generalist. Hands‑on expertise across Linux and Windows environments. Experience working across servers, operating systems, virtualisation and infrastructure layers. Ability to troubleshoot complex technical issues end-to-end. Experience working in Defence, National Security or highly regulated Government environments. Ability to work independently with minimal supervision.Strong judgement and professionalism in high-security contexts. Active TSPV clearance (or recently lapsed and able to be reactivated). Why this role? This opportunity offers: Work within a high-trust Government environment. Technically engaging systems work across multiple layers. A role suited to professionals who enjoy autonomy and responsibility. Immediate start available for cleared candidates. Opportunity to contribute to systems supporting critical national capabilities. Due to the secure nature of this work, only candidates holding an active or reactivatable TSPV clearance can be considered. #J-18808-Ljbffr