Senior Enterprise Systems Administrator & Security Owner

Shieldai; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

Shield AI is seeking a highly autonomous Staff Systems Administrator to own enterprise IT infrastructure and end-user computing in a security-sensitive entity environment. You will design, implement, secure, and continuously improve on-premises systems, cloud platforms, identities, networks, and endpoints with minimal oversight.

The role blends deep infrastructure ownership with hands-on service delivery, translating security and compliance into durable controls and audit-ready evidence for

Qualifications

• 12+ years in systems administration or related field.
• Proven ownership of production IT infrastructure in security-sensitive environments.
• Experience with Windows, macOS, Linux; Azure and/or AWS; AD/Entra ID.

Responsibilities

• Own on-prem and cloud infrastructure, with security-focused controls.
• Implement patching, vulnerability remediation, and hardening.
• Lead identity, endpoint management, and service delivery.
• Document architecture, ownership, and change activities.
• Support audits, incident response, and disaster recovery.

Skills

Windows

macOS

Linux

Azure

AWS

Active Directory

Intune

Jamf

EDR/XDR

Firewalling

Networking

Scripting

Documentation

Tools

Azure

AWS

Intune

Jamf

SIEM

PAM

GitHub/Azure DevOps

Job description

Shield AI is seeking a highly autonomous Staff Systems Administrator to own enterprise IT infrastructure and end-user computing in a security-sensitive entity environment. You will design, implement, secure, and continuously improve on-premises systems, cloud platforms, identities, networks, and endpoints with minimal oversight.

The role blends deep infrastructure ownership with hands-on service delivery, translating security and compliance into durable controls and audit-ready evidence for