Senior IT Platform Architect: M365, Azure & Identity

Colt Technology Services Group Ltd.

Greater London

On-site

GBP 70,000 - 95,000

Full time

12 days ago

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Job summary

Colt Technology Services Group Ltd. is seeking a Senior IT Infrastructure Engineer to lead the engineering, implementation, and operational support of Microsoft 365, Azure, Exchange Online and Identity platforms.

You will deliver secure, automated, and resilient cloud solutions, collaborate across Architecture, Security, Development and Operations, and participate in an on-call rota to ensure 24/7 platform reliability.

Qualifications

Extensive experience in engineering and supporting Exchange Online, Identity, workplace, and Azure Cloud.
Strong expertise across: Microsoft 365 configuration, administration, and security.
Strong expertise in Exchange Online and Microsoft 365 administration.
Experience with Defender for Office 365 and Exchange Online Protection.
Understanding of email authentication technologies including SPF, DKIM, and DMARC.
Experience with Purview, Compliance Center, and retention policies.
Manage mail flow, connectors, transport rules, accepted domains, and email security policies.
Perform tenant-level Exchange administration using EAC and PowerShell.
Identity and access (Active Directory, Entra ID, authentication, access control)
Support identity integration with Entra ID (Azure AD), AD, and AAD Connect.
Security configuration and resilience practices
Automation and operational tooling (PowerShell, scripts, IaC concepts)
Strong troubleshooting and problem-solving capability
Experience working in enterprise-scale environments.

Responsibilities

Implement and operate infrastructure and platform solutions aligned to architectures, standards, and patterns.
Build, configure, and operate end-to-end cloud, M365, and identity solutions.
Act as senior escalation points for engineering and operational issues.
Implement and operate secure-by-design configurations.
Ensure resilience, recoverability, monitoring, and operational readiness are delivered and sustained.
Deliver and operate roadmap initiatives and platform improvements.
Support planning and execution of engineering and operational changes.
Work with Architecture, Security, Development, and Infrastructure teams to deliver integrated solutions.
Ensure solutions are tested, transitioned, and fully operational.
Work with vendors to support implementation, operation, and issue resolution.
Contribute to platform, tooling, and operational improvements.
Ensure solutions align to standards and are maintained through BAU lifecycle.
Support incident, problem, and continuous service improvement activities.
Implement and operate automation-first solutions.
Reduce manual effort, technical debt, and complexity.
Improve stability, consistency, and operational efficiency at scale.
Participate in an on-call rota for priority incident support.
Ownership & Execution: Delivers reliable, secure solutions end-to-end, translating design into high-quality implementation.
Technical Leadership: Acts as SME across cloud, M365, and identity, resolving complex technical challenges.
Collaboration & Influence: Works effectively across teams, contributing to design decisions and stakeholder outcomes.
Adaptability & Improvement: Responds to challenges while driving automation, optimisation, and clear communication.