Senior 3rd Line IT Engineer - M365 & Security

HartleyCo Ltd; West of England, Bath; On-site; GBP 65,000 - 83,000; Full time

Job summary

HartleyCo Ltd. is seeking a 3rd Line IT Support Engineer for an initial 3‑month contract in Bristol. You will provide advanced technical support, manage AD/Entra ID/M365, and drive patching and security controls across hybrid environments.

The role emphasizes strong troubleshooting, documentation, and collaboration with 1st/2nd line teams, with a focus on Cyber Essentials compliance and secure endpoint management.

Qualifications

• 3rd Line IT Support or similar experience required.
• Strong hands-on with AD, Entra ID, and M365 administration.
• Experience with Intune administration and patch management.
• Cyber Essentials compliance knowledge and implementation.
• Windows Server 2012/2016/2019/2022 administration and troubleshoot.
• Fundamental networking knowledge (DNS, DHCP, TCP/IP).
• Excellent communication and documentation skills.

Responsibilities

• Provide 3rd line technical support across client environments.
• Administer and troubleshoot Microsoft 365, AD, Entra ID and Intune.
• Manage patching and updates across Windows servers and endpoints.
• Identify and remediate vulnerabilities and ensure compliance.
• Support Cyber Essentials compliance and security controls.
• Configure endpoint management and security policies in Intune.
• Troubleshoot infrastructure issues (DNS/DHCP, Group Policy, Windows Server).
• Manage user identities and access across on-prem and cloud.
• Assist 1st/2nd line engineers and document technical work.
• Support infrastructure upgrades and security projects.

Skills

Microsoft 365 administration

Active Directory

Entra ID

Microsoft Intune

Patch management

Cyber Essentials

Windows Server administration

Networking basics (DNS/DHCP/TCP/IP)

Troubleshooting

Documentation & comms

Tools

WSUS

SCCM

Azure

Microsoft Defender

Job description

HartleyCo Ltd. is seeking a 3rd Line IT Support Engineer for an initial 3‑month contract in Bristol. You will provide advanced technical support, manage AD/Entra ID/M365, and drive patching and security controls across hybrid environments.

The role emphasizes strong troubleshooting, documentation, and collaboration with 1st/2nd line teams, with a focus on Cyber Essentials compliance and secure endpoint management.