IT System Administrator

Senior IT Systems Administrator

Location: Gloucestershire, UK (On-Site)

Employment Type: Full-time, Mid-Senior level

About the Opportunity

Sanderson is collaborating with a leading global technology organisation that delivers mission-critical services in secure environments for government and national security clients. The team is expanding and seeking a skilled Senior IT Systems Administrator to join a high-performance environment supporting critical infrastructure operations.

In this role, you’ll work across multiple teams to ensure stability, performance, and compliance across enterprise systems — maintaining secure IT environments and helping drive continual service improvement through innovation and best practice.

Key Responsibilities

• Provide 1st and 2nd line technical support across complex IT environments
• Monitor system performance to ensure uptime, reliability, and efficiency
• Develop, maintain, and update system documentation
• Implement and enforce operational standards, policies, and procedures
• Support compliance initiatives and internal process improvements

Essential Skills & Experience

• Strong background in Windows Server Administration (2016/2019)
• Experience working to ITIL best practices
• Excellent organisational and time management skills
• Analytical mindset with a proactive approach to identifying risks and improvements
• Strong communication and collaboration skills, with a willingness to share and learn

Desirable Technologies & Experience

• Installation, upgrade, configuration, and support experience with Windows Server, AWS, and Azure
• Strong understanding of Active Directory (object creation, OU management, RBAC, DFS)
• Knowledge of virtualisation technologies : VMware, vSphere, vSAN, SCVMM, Hyper-V
• Familiarity with containerisation tools and technologies
• Networking fundamentals: TCP/IP, DHCP, DNS, LAN/WAN
• Scripting experience in PowerShell
• Awareness of McAfee EPO/ENS security tools

Security Clearance Requirements

Due to the nature of the work, candidates must be eligible for national security clearance . To meet this requirement, applicants must:

• Be sole British citizens (dual nationality is not permitted)
• Have not spent more than 30 consecutive days outside the UK in the past 10 years
• Have no criminal record
• Have no significant financial irregularities (e.g. bankruptcy, unpaid debt)

Unfortunately, candidates who do not meet these criteria cannot be considered for this position.

Why You’ll Enjoy Working Here

• Competitive salary and comprehensive benefits package
• Hybrid working model balancing flexibility and collaboration
• Career growth opportunities through continuous learning and development
• Work on high-impact, nationally significant projects
• Inclusive, people-first culture focused on wellbeing and professional excellence