Senior Systems Administrator - Windows/Linux, IAM & On-Call

Shield; Greater London; On-site; GBP 42,000 - 64,000; Full time

Job summary

Shield AI seeks a Systems Administrator to support, secure, and optimize enterprise IT operations across Windows and Linux environments. The role includes hands-on administration, asset lifecycle management, and mentoring junior staff in a modern, scalable IT setup.

You will collaborate with infrastructure, network, and security teams, participate in on-call rotations, and contribute to technical documentation and training, ensuring compliance and service reliability.

Qualifications

• 3+ years of systems administration or enterprise desktop support.
• Proficient in Windows and Linux operating systems.
• Experience with AD, Azure AD and IAM tools.
• Solid networking fundamentals and security practices.
• Familiarity with IT asset management platforms.

Responsibilities

• Provide hands-on desktop, server, and systems administration support for Windows and Linux environments.
• Install, configure, and troubleshoot hardware and software across end-user devices and server systems.
• Administer user accounts, access control, and group policies using Active Directory and Azure AD.
• Manage IT assets lifecycle: procurement, deployment, support, and decommissioning.
• Ensure inventory, licensing compliance, and asset tracking using ITAM tools.
• Lead and mentor junior admins; contribute to documentation and training.

Skills

Windows OS

Linux OS

Active Directory

Azure AD

Networking basics

IT asset management

On-call support

Documentation

Collaboration

Customer service

Tools

SNIPE

JSM

JIRA

Intune

JAMF

Job description

Shield AI seeks a Systems Administrator to support, secure, and optimize enterprise IT operations across Windows and Linux environments. The role includes hands-on administration, asset lifecycle management, and mentoring junior staff in a modern, scalable IT setup.

You will collaborate with infrastructure, network, and security teams, participate in on-call rotations, and contribute to technical documentation and training, ensuring compliance and service reliability.