Senior Systems Engineer – L3 Escalation Support

About the role

Our client is a security‑focused Managed IT and Managed Security Services provider serving organisations across the United States. They are seeking a Senior Systems Engineer (L3 / Escalation Support) to act as the primary technical escalation point for Level 1 and Level 2 technicians, handling complex issues in Microsoft, server, network, endpoint, cloud and security environments while communicating directly with U.S. clients.

Key responsibilities

• Serve as the senior escalation point for Level 1 and Level 2 technicians.
• Troubleshoot advanced endpoint, server, network, Microsoft 365, cloud, application and security problems.
• Perform root‑cause analysis, document resolutions and mentor junior staff.
• Proactively monitor client environments, investigate alerts and conduct preventive maintenance.
• Administer and support Microsoft 365 services, including Entra ID, Exchange Online, Teams, SharePoint and Defender.
• Manage Windows Server, Active Directory, Group Policy and virtualisation platforms (VMware, Hyper‑V).
• Support networking components such as DNS, DHCP, VLANs, VPNs, routing, switching and firewalls.
• Monitor security alerts, investigate EDR/MDR incidents and verify backup health.
• Develop and maintain PowerShell and Microsoft Graph scripts to automate routine tasks.
• Communicate status and technical details clearly to U.S. clients and their IT teams.

Required profile

• 5+ years of professional IT infrastructure and support experience (preferred).
• 3+ years in senior systems administration or Level 3 escalation roles.
• Strong hands‑on troubleshooting of complex technical issues.
• Deep experience with Microsoft Windows and Microsoft 365 environments.
• Proficiency with Windows Server, Active Directory and Group Policy.
• Solid networking fundamentals (TCP/IP, DNS, DHCP, VPN, VLAN, routing, switching, firewalls).
• Experience with cybersecurity and endpoint security tools.
• Excellent written and spoken English and client‑facing communication skills.
• Ability to manage multiple priorities in a fast‑paced managed‑services setting.
• Reliable remote‑work setup with appropriate security controls.

Required skills

• Microsoft 365
• Microsoft Entra ID
• Exchange Online
• Microsoft Teams
• SharePoint
• OneDrive
• Microsoft Defender
• PowerShell
• Microsoft Graph
• Windows Server
• Active Directory
• Group Policy
• DNS
• DHCP
• TCP/IP
• VLANs
• VPNs
• Routing
• Switching
• Firewalls
• VMware
• Hyper‑V
• Datto RMM
• Autotask PSA
• IT Glue
• Datto EDR
• Kaseya MDR
• RocketCyber
• Datto Backup
• UniFi
• SonicWall
• Fortinet
• Cisco
• Veeam
• Axcient