Systems Administrator (IT Infrastructure)

Ci4 builds autonomous platforms and the AI autonomy stack that runs them, handling complex, dangerous or repetitive tasks across maritime and land domains. We are looking for a hands-on Systems Administrator to own our IT end to end: designing and setting up the infrastructure as the company grows, and then running it reliably and securely.

This is not a help-desk role. You will build our IT environment from the ground up, decide how resources are set up and shared, and keep everything running for an engineering-heavy team working on defense and underwater systems.

What you will do

• Set up, configure and maintain our standalone in-house servers, including OS installation, patching, backups, monitoring and access control
• Administer Microsoft 365 and Google Workspace: tenants, user and group lifecycle, email, shared drives, permissions, and sharing policies
• Design and implement how files, data and compute resources are shared across teams, with sensible access controls and audit trails
• Manage software licensing and subscriptions, including AI tools and engineering/productivity software: procurement, renewals, seat allocation and distribution to the right people
• Maintain the IT asset inventory, covering laptops, workstations, servers, printers, networking gear, peripherals and other hardware, along with assignment, tracking and lifecycle (onboarding, replacement, retirement)
• Manage office networking: LAN/Wi-Fi, firewall, VPN and remote access, and printers and shared devices
• Onboard and offboard employees with accounts, devices and access provisioned and revoked promptly
• Implement and document security basics: endpoint protection, MFA, password policies, device encryption, backup and recovery procedures
• Act as the point of contact for IT support, troubleshoot issues, and coordinate with vendors
• Write and maintain clear documentation, runbooks and IT policies
• Advise leadership on IT tooling, cost and scaling needs as the company grows

Required

• 5+ years of experience as a systems administrator or IT administrator, with demonstrated experience setting up infrastructure rather than only maintaining it
• Hands-on administration of Microsoft 365 and Google Workspace (admin consoles, identity, email, storage, sharing and permission management)
• Experience setting up and managing on-premise servers (Windows Server and/or Linux), including user management, file sharing, backups and patching
• Solid understanding of networking fundamentals: TCP/IP, DNS, DHCP, VLANs, firewalls, VPN
• Experience managing software licenses and SaaS subscriptions, and tracking IT assets and hardware inventory
• Strong troubleshooting skills across hardware, OS, network, and peripherals including printers
• Working knowledge of IT security practices: MFA, endpoint protection, access control, encryption, backup and recovery
• Clear written communication and the ability to document systems and processes
• Ability to work independently, prioritise, and own outcomes in a small, fast-moving team

Nice to have

• Experience with Active Directory / Entra ID, SSO, and device management tools (Intune, MDM)
• Experience supporting engineering teams, including GPU workstations or compute servers
• Scripting and automation skills (PowerShell, Bash, or Python)
• Familiarity with virtualization (Proxmox, VMware, Hyper-V) and NAS/storage systems
• Experience in a defense, aerospace, or other security-sensitive environment, with an understanding of data-handling and compliance requirements
• Relevant certifications (e.g., Microsoft 365, CompTIA, CCNA, RHCSA)