Senior Unix Systems Administrator / Infrastructure Engineer (EL1)

Location: QLD, ACT, VIC, NSW, SA

Security Clearance: Must have NV1 Clearance

Role Summary

The Senior Unix Systems Administrator / Infrastructure Engineer is responsible for the implementation, management, optimisation and retirement of enterprise UNIX and Linux infrastructure that supports mission‑critical digital services. This role provides senior‑level technical leadership in a 24/7 operational environment and ensures infrastructure platforms are secure, resilient, scalable and compliant with government and organisational standards, including the Essential Eight.

The role works closely with delivery teams, operations, security and architecture functions, and provides mentoring to junior engineers while contributing to complex design, installation and problem‑resolution activities.

Key Responsibilities

Infrastructure Operations & Availability

• Manage and maintain Midrange UNIX and Linux infrastructure supporting mission‑critical services.
  
• Ensure high availability, performance and reliability of systems operating in a 24/7 environment.
  
• Provide senior BAU operational support, including participation in on‑call and after‑hours support during critical periods.
  

Capacity Management

• Monitor infrastructure capacity (CPU, memory, storage and network utilisation).
  
• Identify capacity constraints and initiate corrective actions in line with agreed procedures.
  
• Contribute to capacity modelling, forecasting and infrastructure planning activities.
  

Incident, Problem & Change Management

• Perform complex incident response, problem investigation and root‑cause analysis.
  
• Determine and implement permanent fixes and preventative measures.
  
• Support trend analysis to improve service stability and problem management practices.
  
• Implement approved infrastructure changes and maintenance activities in accordance with ITSM processes.
  

Infrastructure Engineering & Automation

• Install, configure, maintain and decommission UNIX/Linux systems and associated infrastructure.
  
• Develop and maintain scripts and automation (e.g. shell, Python) to support provisioning, deployment, monitoring and compliance.
  
• Use infrastructure management and monitoring tools to analyse system performance and health.
  

Systems Design & Installation

• Design and review large or complex infrastructure solutions, including impact analysis and trade‑off assessments.
  
• Ensure designs balance functional and non‑functional requirements such as availability, security, performance and recoverability.
  
• Lead installation and decommissioning activities, including planning, execution, validation and documentation.
  
• Manage risks associated with infrastructure changes and installations.
  

Security & Compliance

• Implement infrastructure hardening and security controls aligned with the Essential Eight.
  
• Support audits, compliance assessments and remediation activities.
  
• Ensure operational procedures align with security policies and government standards.
  

Leadership & Collaboration

• Provide technical leadership and mentoring to junior infrastructure engineers.
  
• Collaborate with stakeholders across infrastructure, security, delivery and architecture teams.
  
• Maintain clear documentation, operational procedures and knowledge artefacts.
  

Required Skills & Experience

• Extensive experience administering and engineering UNIX/Linux environments in large, complex organisations.
  
• Strong capability in enterprise infrastructure operations, performance monitoring and troubleshooting.
  
• Proven experience with scripting and automation to support infrastructure lifecycle activities.
  
• Experience designing and implementing secure, resilient infrastructure solutions.
  
• Strong understanding of IT service management, problem management and operational best practice.
  
• Demonstrated ability to work effectively in high‑pressure, 24/7 environments.