Senior Engineer 3rd Line – IT Support London Jobs

Senior Engineer 3rd Line – IT Support London Jobs – About the role

As a 3rd Line Infrastructure Engineer at Speedster IT, you’ll be at the sharp end of our managed services delivery. You’ll own the day-to-day health of our clients’ IT environments — from physical hardware to cloud-hosted services — and act as a trusted technical partner to the businesses we support. This is a hands-on, client-facing role where no two days are the same.

Key responsibilities

Infrastructure operations

Provide hands-on support for client IT environments including servers, networks, and end-user systems. Monitor and maintain internal and external networks, email platforms, and security systems. Proactively identify and address risks before they impact client operations.

Deployments & maintenance

Configure and deploy new server systems, hardware, and software in client environments. Carry out scheduled maintenance including patch management, updates, and backup and recovery operations. Manage system restarts and recovery procedures following outages or failures, minimising downtime at every stage.

3rd line fault resolution

Diagnose and resolve complex technical faults escalated from 1st and 2nd line support. Where issues fall outside your remit, escalate to senior engineers or third-party vendors with thorough documentation of all steps taken. Serve as the key liaison between clients, external suppliers, and internal technical teams — keeping all parties informed throughout.

Performance & documentation

Analyse system performance data and identify opportunities to improve the reliability, security, or efficiency of client environments. Maintain accurate technical documentation including configuration records, change logs, and incident reports — keeping our knowledge base current and audit-ready at all times.

What we’re looking for

• Proven experience at 2nd or 3rd line in an MSP environment
• Strong knowledge of Windows Server, Active Directory, and networking fundamentals
• Experience with Microsoft 365, Azure, and cloud-based infrastructure
• Confident working with firewalls, switches, and security tooling
• Clear written and verbal communication — with both technical and non-technical audiences
• A methodical approach to troubleshooting with thorough documentation habits

Nice to have

Relevant certifications such as Microsoft (MCSA / AZ-series), CompTIA (Network+, Security+), or Cisco (CCNA) are advantageous. Experience with RMM platforms (e.g. ConnectWise, Datto, NinjaRMM) and familiarity with ITIL practices would also be a plus.

Why Speedster IT?

We’re a fast-growing MSP with a reputation for doing things properly. You’ll work across a varied client base, have real ownership of your projects, and be supported by a team that values technical depth as much as great service. We invest in our engineers — from training and certifications to the tools you need to do your best work.