3rd Line Network Engineer

IMT Resourcing Solutions; Bishopsgate; Hybrid; GBP 45,000 - 50,000; Full time

Benefits offered by this job

Share scheme

Private healthcare

Pension

25 days annual leave

Job summary

IMT Resourcing Solutions in London is seeking a 3rd Line Network Engineer to provide senior-level technical support across complex customer networks. The role is hybrid based in London, with exposure to routing, switching, wireless and connectivity technologies.

You will own escalated faults, document changes under change control, and work with customers and field engineers to diagnose and resolve incidents.

Qualifications

• Strong experience in 3rd Line Network Support or senior Network Engineering roles.
• Ideally has ISP/service provider environment exposure.
• Solid fundamentals in routing, switching, TCP/IP and BGP.
• Able to troubleshoot complex network faults methodically (not just scripts).
• Hands-on experience configuring carrier/enterprise-grade equipment and making live changes.
• Good change control, documentation and config management practices.
• Experience owning customer-impacting incidents from escalation to resolution.
• Excellent written and verbal communication, able to explain technical issues to non-technical customers.
• Experience troubleshooting enterprise wireless networks and remote diagnostics.
• Scripting or API knowledge for diagnostics/automation.
• Understanding of Layer 1 fibre networks and network monitoring/ticketing platforms.
• Relevant certifications across routing & switching, firewalls and/or wireless networking.

Responsibilities

• Own complex/escalated network faults through to full resolution.
• Troubleshoot routing, switching, wireless, and customer network infrastructure.
• Make and document changes on live customer equipment under change control.
• Collaborate with customers, field engineers, suppliers and internal network teams to diagnose incidents.
• Troubleshoot wireless issues remotely; support on-site surveys and access point placement.
• Develop deep technical knowledge across wireless platforms.
• Escalate core network issues to Network Operations with diagnosis & impact.
• Monitor events with potential impact across multiple customers and correlate with incidents.
• Lead problem management for recurring faults and provide root cause analysis.
• Produce RCA/Reason for Outage documentation for customer-facing incidents.
• Develop technical playbooks to improve resolution rates across 1st/2nd line.
• Improve monitoring/alerting by tuning thresholds and reducing unnecessary alerts.
• Manage escalations with third-party suppliers and connectivity providers.
• Provide input on complex customer configurations before go-live.
• Participate in on-call rota as senior escalation point behind 2nd line.

Skills

3rd Line Core Network Support

Advanced 2nd Line

Senior Network Engineer

ISP/Service Provider experience

Routing & Switching

TCP/IP

BGP

Troubleshooting complex faults

Live network changes

Change control & docs

Incident ownership

Wireless networking

Remote wireless diagnostics

Scripting / API

Layer 1 fibre

Network monitoring/alerts/tickets

Certifications in routing/firewall/wir

Job description

Salary: £45,000 - 50,000 per year

Requirements

• 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
• 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

Responsibilities

• 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 our 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

Technologies

• API
• Support
• Network
• TCP/IP

More:

We are a leading London-based connectivity and technology organisation hiring a 3rd Line Network Engineer to provide senior-level technical support across business-critical customer networks. This is a hybrid role based in London, offering a salary of up to £50,000, plus a share scheme, private healthcare, pension, and 25 days annual leave plus bank holidays. You will work closely with 1st and 2nd Line Support, Network Operations, field engineering teams, third-party suppliers and customers, taking ownership when incidents require deeper technical investigation. The role offers hands-on exposure to live customer-facing network environments, the chance to work across routing, switching, wireless and connectivity technologies, and support towards advanced professional networking certifications.

last updated 36 week of 2026