3rd Line Network Engineer

3rd Line Network Engineer

Location: London - Hybrid Working

Salary: Up to £50,000

Benefits: Share scheme, private healthcare, pension, 25 days' annual leave + bank holidays

Our client, a leading London-based connectivity and technology organisation, is hiring a 3rd Line Network Engineer to provide senior-level technical support across business-critical customer networks.

Sitting at the top technical tier of the support function, you'll take ownership of complex network faults requiring deeper expertise across routing, switching, wireless and customer-facing network infrastructure.

You’ll own escalated incidents through to resolution, make configuration changes on live network equipment and investigate recurring problems to identify and implement permanent fixes.

Beyond resolving individual incidents, you’ll help improve the wider support operation, developing technical playbooks, improving monitoring and giving 1st and 2nd Line teams the knowledge they need to resolve more issues without escalation.

What you'll do

• Own complex and escalated network faults through to full resolution
• Troubleshoot issues across routing, switching, wireless and customer network infrastructure
• Make and document configuration changes on live customer-facing network equipment under change control
• Work with customers, field engineers, suppliers and internal network teams to diagnose and resolve incidents
• Troubleshoot wireless issues remotely, supporting engineers on-site with surveys, access point placement, cabling and power checks
• Develop deep technical knowledge across the organisation's wireless networking platforms
• Escalate core network issues to Network Operations with the diagnosis and customer impact already established
• Monitor network events with the potential to impact multiple customers and correlate these against incoming incidents
• Lead problem management for recurring faults, identifying root causes and driving permanent fixes
• Produce clear Root Cause Analysis (RCA) and Reason for Outage documentation for customer-facing incidents
• Develop technical playbooks and documentation to improve resolution rates across 1st and 2nd Line Support
• Improve network monitoring and alerting by tuning thresholds, reducing unnecessary alerts and identifying gaps in coverage
• Manage technical escalations with third-party suppliers and connectivity providers
• Provide technical input on complex customer network configurations before they go live
• Participate in the on-call rota as the senior technical escalation point behind 2nd Line

You’ll work closely with 1st and 2nd Line Support, Network Operations, field engineering teams, third-party suppliers and customers, taking ownership when an incident requires deeper technical investigation.

What we're looking for

Essential:

• Strong experience within 3rd Line Network Support, advanced 2nd Line or a senior Network Engineering role
• Ideally, experience within an ISP, telecoms, carrier or service provider environment
• Strong routing and switching fundamentals, including TCP/IP and BGP
• Ability to troubleshoot complex network faults methodically rather than relying solely on predefined scripts
• Hands-on experience configuring carrier or enterprise-grade network equipment
• Experience making changes to live, customer-facing network infrastructure
• Good understanding of change control, technical documentation and configuration management
• Experience owning customer-impacting incidents from escalation through to resolution
• Strong written and verbal communication skills, including the ability to explain technical problems clearly to non-technical customers

Desirable:

• Experience troubleshooting enterprise wireless networks
• Experience carrying out remote wireless diagnostics while supporting engineers on-site
• Scripting or API knowledge for network diagnostics and automation
• Understanding of Layer 1 fibre networks
• Experience with network monitoring, alerting and ticketing platforms
• Relevant professional certifications across routing & switching, firewalls and/or wireless networking

You don't need to hold every certification from day one. Our client will support continued professional development and expects engineers to work towards relevant advanced networking certifications after joining.

Why join?

• Operate as a senior technical escalation point for complex network incidents
• Work across routing, switching, wireless and connectivity technologies
• Gain hands-on exposure to live customer-facing network environments
• Take ownership of incidents rather than simply escalating tickets
• Develop deeper expertise across enterprise and service provider networking
• Play a direct role in improving monitoring, processes and technical knowledge across the support function
• Support towards advanced professional networking certifications
• Employee share scheme and company bonus
• Private healthcare, life assurance and income protection
• 25 days' annual leave, increasing with service, plus bank holidays
• Company pension and additional wellbeing benefits

This would suit an experienced 3rd Line Network Engineer or advanced 2nd Line Network Engineer who enjoys getting into complex technical problems, taking ownership of incidents and finding the root cause rather than applying temporary fixes.