Senior IT Support Engineer (3rd Line) — London

Our client is a global alternative investment firm focused on the metals and materials that underpin the energy transition and sustainable economic growth. With deep sector specialization and a presence across major financial centers, the firm partners with sophisticated institutional investors on the kind of tailored investment solutions most generalist managers simply can't offer. It's a lean, high-caliber team — and as the London office grows, they need a senior technical partner to keep IT running seamlessly behind the scenes.

What You'll Do

• Act as the primary buffer between the support desk and the Infrastructure Manager — the main point of escalation for issues that need a senior set of hands.
• Diagnose server and network issues (troubleshooting, not architecture/design), and own patch management and endpoint security administration across the estate.
• Lead infrastructure-adjacent projects such as network refreshes, cloud migration support, and M365 tenant administration.
• Manage day-to-day vendor and support contract relationships and renewals.
• Own the security patching cadence, endpoint protection, and compliance reporting, using PowerShell/scripting to automate routine work wherever it makes sense.
• Support office moves, technology rollouts, and small projects as they come up.
• Step into 1st/2nd line fundamentals when needed — ticket triage, password resets, new starter/leaver setup, Active Directory/Entra and Microsoft 365 administration, mobile device management (Intune/Jamf), and basic network troubleshooting (WiFi, VPN, switches).
• Mentor junior team members as the team grows.
• Keep SOPs written and current.