Information Technology Support Engineer

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

Job Title: Band 3 – L3 Desktop Support Technician

Job Summary

The L3 Desktop Support Technician is responsible for providing advanced technical support and resolving complex desktop, laptop, operating system, application, and peripheral issues. The role serves as a senior escalation point for L1/L2 support teams, performs root cause analysis, drives problem resolution, and contributes to IT infrastructure projects, system upgrades, and continuous improvement initiatives.

The technician will work closely with infrastructure, network, security, application, and other IT teams to ensure high availability, security, and optimal performance of end-user computing environments.

Key Responsibilities:

• Provide L3/third-level technical support for complex Windows and Mac desktop/laptop hardware, software, operating system, and peripheral issues.
• Act as a senior escalation point for issues that cannot be resolved by L1/L2 support teams.
• Perform advanced troubleshooting and root cause analysis (RCA) for recurring and critical technical issues.
• Diagnose and resolve complex Windows and macOS break/fix issues, including operating system, drivers, applications, hardware, and system configuration.
• Install, configure, upgrade, and maintain operating systems, applications, patches, drivers, and endpoint configurations.
• Troubleshoot advanced LAN/WAN, Wi-Fi, VPN, DNS, DHCP, and network connectivity issues in coordination with network teams.
• Support Active Directory, Group Policy, user accounts, permissions, and endpoint-related configuration issues.
• Provide advanced remote support for users working from home, remote locations, or field environments.
• Investigate recurring incidents and recommend permanent corrective actions to reduce incident volume.
• Participate in major incident resolution and provide technical assistance during critical outages.
• Collaborate with infrastructure, network, cybersecurity, application, and other IT teams to resolve cross-functional technical issues.
• Support IT projects, migrations, hardware refreshes, operating system upgrades, application deployments, and new technology implementations.
• Assist with endpoint security, vulnerability remediation, patch management, and compliance activities.
• Maintain accurate and detailed records of incidents, troubleshooting steps, root causes, and resolutions in the ticketing system.
• Identify opportunities for process improvement, automation, standardization, and enhancement of the end-user computing environment.
• Develop and maintain technical documentation, knowledge articles, troubleshooting guides, and standard operating procedures.
• Mentor and provide technical guidance to L1/L2 desktop support technicians.
• Ensure adherence to IT policies, security standards, change management processes, and operational best practices.
• Perform routine health checks, maintenance, and inspections of desktop/laptop environments and endpoint devices.
• Monitor recurring technical issues and provide recommendations to management for long-term resolution.
• Build strong relationships with end users and stakeholders while maintaining a high level of customer satisfaction.
• Participate in an on-call or escalation support rotation, where required.

Qualifications

• Bachelor's degree in Information Technology, Computer Science, or a related field, or equivalent practical experience.
• 4–7 years of experience in desktop support, EUC, endpoint support, or a similar IT support role.
• Strong hands-on experience supporting Windows and macOS environments.
• Advanced knowledge of desktop/laptop hardware, operating systems, peripherals, drivers, and software applications.
• Strong experience troubleshooting complex Windows and Mac break/fix issues.
• Good understanding of Active Directory, Group Policy, user account management, permissions, and endpoint configuration.
• Strong understanding of networking concepts including TCP/IP, DNS, DHCP, LAN/WAN, Wi-Fi, and VPN.
• Experience with remote support and remote desktop tools.
• Experience working with enterprise ticketing/ITSM platforms such as ServiceNow or similar tools.
• Knowledge of endpoint management and deployment tools such as Microsoft Intune, SCCM/MECM, Jamf Pro, or equivalent is an advantage.
• Understanding of endpoint security, patching, vulnerability remediation, and IT security best practices.
• Experience performing root cause analysis, problem management, and advanced troubleshooting.
• Strong analytical, troubleshooting, and problem-solving skills.
• Excellent written and verbal communication skills.
• Ability to work independently, manage priorities, and handle complex technical escalations.
• Ability to collaborate effectively with cross-functional IT teams and business stakeholders.
• Experience mentoring or providing technical guidance to junior support engineers/technicians.

Preferred Certifications

• CompTIA A+
• CompTIA Network+
• ITIL Foundation
• Apple Certified Support Professional or relevant Apple certifications
• Other relevant Microsoft, Apple, networking, or endpoint-management certifications