3rd Line Support Engineer

Hamilton Barnes ?; Greater London; On-site; GBP 50,000 - 70,000; Full time

Benefits offered by this job

Ongoing technical training

Structured learning pathways

Supportive team culture

Job summary

A leading technical services company in Greater London is looking for a Senior 3rd Line Support Engineer. You will be the go-to technical expert, managing complex incidents onsite for a high-profile client. Responsibilities include full ownership of technical resolutions and mentoring junior engineers. Candidates should be proficient in Microsoft Exchange, Microsoft 365, and possess advanced networking knowledge. Opportunities for continuous learning and professional development are offered.

Qualifications

• Proven experience in a senior support role onsite at client premises.
• Strong hands-on with Microsoft Exchange and Microsoft 365.
• Advanced networking knowledge required.

Responsibilities

• Act as the senior onsite escalation point for complex technical incidents.
• Manage investigation, diagnosis, and resolution of 3rd line issues.
• Support internal infrastructure and project work.

Skills

Microsoft Exchange

Microsoft 365

TCP/IP

Routing

Switching

NGFWs

VPN

VMware

iSCSI

Active Directory

DNS

DHCP

Group Policy

SharePoint Online

Teams

OneDrive

Leadership

Job description

Are you a senior support engineer who enjoys being the go-to technical expert on site, rather than sitting in endless ticket queues?

This 3rd Line Support Engineer role places you onsite with a high-profile infrastructure client in London, acting as the highest technical escalation point. You’ll work hands-on with complex technical issues while also contributing to project work, service improvement initiatives, and the development of junior engineers.

You’ll gain exposure to large-scale, enterprise environments, have genuine technical ownership, and be part of a team that values quality delivery, progression, and professional development.

What You’ll Be Doing

• Acting as the senior onsite escalation point for complex technical incidents
• Owning investigation, diagnosis, and resolution of 3rd line issues
• Supporting and managing internal infrastructure alongside ad-hoc project work
• Providing technical leadership through mentoring and guidance of junior engineers
• Managing client expectations through clear, professional communication
• Ensuring incidents, changes, and time entries are accurately logged
• Maintaining and updating technical documentation as environments evolve
• Working closely with the Service Delivery Manager to align on service standards
• Supporting continuous service improvement and wider team objectives

What We’re Looking For

• Proven experience working onsite at a client premises in a senior support capacity
• Strong hands-on experience with Microsoft Exchange and Microsoft 365
• Advanced networking knowledge (TCP/IP, routing, switching, NGFWs)
• VPN experience (site-to-site and remote access)
• Virtualisation expertise, ideally VMware in highly available environments
• SAN and storage technologies (iSCSI, SAN administration)
• Enterprise Applications
• Deep knowledge of Active Directory, DNS, DHCP, and Group Policy
• Administration of SharePoint Online, Teams, and OneDrive
• Confident communicator with the ability to lead and mentor

Why This Role?

• Senior onsite role with real technical authority
• Exposure to complex, enterprise-scale environments
• Structured learning and development pathways
• Ongoing access to technical training and certifications
• Supportive team culture with clear progression opportunities

If you’re looking for onsite ownership, technical depth, and long-term progression, I’d be happy to have a confidential conversation.