Senior System Administrator

About the role

We are seeking a Senior System Administrator to lead the design, implementation and day‑to‑day management of our IT infrastructure. The role combines hands‑on technical work with strategic oversight to ensure high availability, security and performance across on‑premises and cloud environments.

Key responsibilities

• Manage and maintain servers, networks, storage, and endpoint devices.
• Ensure system availability, performance, security and proactive issue resolution.
• Administer Microsoft 365 services including Exchange Online, Teams, SharePoint, OneDrive, Entra ID and Intune.
• Handle user accounts, licenses, MFA, Conditional Access and DLP policies.
• Support Azure and AWS cloud services – provisioning, monitoring, backup and optimisation.
• Install, configure and maintain Windows and Linux servers and virtualization platforms (VMware, Hyper‑V).
• Manage storage systems, backups, disaster recovery and capacity planning.
• Administer Active Directory, DNS, DHCP, Group Policy and hybrid cloud connectivity.
• Maintain IT asset inventory, software licensing, procurement and lifecycle management.
• Support VoIP/PBX solutions such as 3CX, CloudTalk, Cisco, Grandstream and Yealink, including SIP trunks, call routing and IVR.
• Coordinate with IT vendors, manage contracts, SLAs and renewals.
• Implement security controls, endpoint protection, patch management and compliance practices.
• Provide Level 2/3 technical support and keep documentation up to date.

Required profile

• Minimum 6 years of experience in IT infrastructure administration.
• Strong hands‑on expertise with Microsoft 365 and Azure AD/Entra ID.
• Solid background in Windows Server administration and Active Directory.
• Experience with SAN/NAS storage, backup and disaster recovery solutions.
• Proficiency in virtualization technologies (VMware, Hyper‑V).
• Hands‑on experience managing hybrid cloud environments (Azure, AWS).
• Working knowledge of IT asset management tools and processes.
• Experience administering VoIP/PBX systems (3CX, CloudTalk, Cisco, Grandstream, Yealink).
• Good understanding of LAN/WAN networking, firewalls, VPN and routing.
• Familiarity with IT security best practices and compliance frameworks.

Required skills

• Microsoft 365 (Exchange Online, Teams, SharePoint, OneDrive, Intune)
• Azure AD / Entra ID
• Azure and AWS cloud services
• Windows Server, Active Directory, DNS, DHCP, Group Policy
• VMware, Hyper‑V virtualization
• SAN/NAS storage and backup/disaster recovery
• 3CX, CloudTalk, Cisco, Grandstream, Yealink PBX
• LAN/WAN, firewalls, VPN, switching and routing
• Endpoint protection, patch management, compliance
• IT asset management tools