Senior Unix Systems Administrator Infrastructure Engineer (EL1) +

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 missioncritical digital services. This role provides seniorlevel 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 problemresolution activities.

Key Responsibilities

Infrastructure Operations & Availability

• Manage and maintain Midrange UNIX and Linux infrastructure supporting missioncritical services.
  
• Ensure high availability performance and reliability of systems operating in a 24/7 environment.
  
• Provide senior BAU operational support including participation in oncall and afterhours 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 rootcause 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 tradeoff assessments.
  
• Ensure designs balance functional and nonfunctional 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.
  

• 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 highpressure 24/7 environments.