Senior Desktop Support Engineer (Windows & Mac)

SISL Global; Greater London; On-site; GBP 30,000 - 42,000; Full time

Job summary

SISL Global is seeking an L3 Desktop Support Technician to provide advanced end-user support across Windows and macOS environments. You will act as a senior escalation point, perform RCA, and contribute to IT projects and security initiatives.

You will collaborate with IT infrastructure, cyber security, and application teams to maintain high availability and strong user experience, including remote support for field/location workers.

Qualifications

• Bachelor's degree in IT, Computer Science, or related field, or equivalent practical experience.
• 4–7 years of desktop support or EUC experience.
• Strong hands-on support for Windows and macOS environments.
• Advanced knowledge of desktop hardware, OS, peripherals, drivers and software.
• Experience with Windows and Mac break/fix issues.
• Understanding of Active Directory, Group Policy, user accounts, permissions and endpoint configuration.
• Strong networking knowledge: TCP/IP, DNS, DHCP, LAN/WAN, Wi‑Fi, VPN.
• Experience with enterprise ticketing/ITSM like ServiceNow or similar.
• Knowledge of endpoint management tools: Intune, SCCM/MECM, Jamf Pro or equivalent.
• Understanding of endpoint security, patching, vulnerability remediation and IT security best practices.

Responsibilities

• Provide L3/third-level support for Windows and Mac desktop/laptop issues.
• Serve as senior escalation point for L1/L2 teams.
• Perform RCA and advanced troubleshooting for recurring issues.
• Diagnose and resolve complex Windows/macOS break/fix issues.
• Install, configure, upgrade, and maintain OSs, apps, drivers, and endpoint setups.
• Troubleshoot network connectivity with LAN/WAN, Wi‑Fi, VPN, DNS, DHCP.
• Support Active Directory, Group Policy, and user accounts.
• Provide advanced remote support for remote/work-from-home users.
• Contribute to IT projects, migrations, hardware refreshes, and upgrades.
• Mentor L1/L2 technicians and create knowledge guides.

Skills

Experience

Windows

macOS

Active Directory

Group Policy

Network troubleshooting

Remote support

ITSM ticketing

Education

Bachelor's degree in IT or related field

Tools

Intune

SCCM/MECM

Jamf Pro

Remote support tools

Job description

SISL Global is seeking an L3 Desktop Support Technician to provide advanced end-user support across Windows and macOS environments. You will act as a senior escalation point, perform RCA, and contribute to IT projects and security initiatives.

You will collaborate with IT infrastructure, cyber security, and application teams to maintain high availability and strong user experience, including remote support for field/location workers.