IT Infrastructure Platform Architect
Senior IT infrastructure engineer at Colt, engineering and operating Microsoft 365, Azure, Exchange Online and enterprise identity (AD/Entra ID) platforms. Day to day: implementing secure, automated platform solutions, tenant and identity administration, cloud security, and automation with PowerShell, plus on-call incident support.
- Compensation
- Not disclosed
- Location
- London, UK
- Work setup
- Not specified
- Seniority
- Not specified
- Employment
- Not specified
- Experience
- Not specified
- Category
- Architecture
- Posted
Skills
Must have
- Extensive experience engineering and supporting Exchange Online, Identity, workplace, and Azure Cloud
- Strong expertise in Microsoft 365 configuration, administration, and security
- Strong expertise in Exchange Online and Microsoft 365 administration
- Experience with Microsoft Defender for Office 365 and Exchange Online Protection
- Understanding of email authentication technologies (SPF, DKIM, DMARC)
- Experience with Microsoft Purview, Compliance Center, and retention policies
- Manage mail flow, connectors, transport rules, accepted domains, and email security policies
- Tenant-level Exchange administration using Exchange Admin Center (EAC) and PowerShell
- Azure cloud engineering (deployments, governance, connectivity)
- Identity and access expertise (Active Directory, Entra ID, authentication, access control)
- Support identity integration with Microsoft Entra ID, Active Directory, and Azure AD 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
- Participate in an on-call rota for priority incident support
Full description
Why we need this role
The Senior IT Infrastructure Engineer (M365, Azure, Exchange online & Identity) is responsible for the engineering, implementation, and operational support of Microsoft 365, Azure, Exchange online and enterprise identity (AD/Entra).
The role delivers secure, standardised, and automated solutions, translating architectural designs, standards, and roadmaps into robust, scalable platform implementations and operational services.
Working as a senior technical expert within the engineering team, the role collaborates with Architecture, Security, Development, and Operations teams to ensure solutions are delivered, integrated, and operated effectively.
It embeds security, resilience, automation, and operability by implementation, driving consistency and optimisation across M365, Azure, Exchange online, and Identity platforms. Through engineering excellence, the role reduces risk, complexity, and manual effort, improves resilience and service stability, and supports cost-efficient platform operations.
What you will do
Engineers and supports solutions across M365, Azure, Exchange online and Identity, ensuring platforms, tooling, interfaces, and configurations are secure, resilient, automated, and operationally effective.
- Microsoft 365 Platforms: Implementation, configuration, and support of collaboration and productivity services (inc. Teams, Exchange, SharePoint, OneDrive, Intune), including governance controls, security settings, and lifecycle activities
- Azure Cloud: Deployment and support of landing zones, subscriptions, connectivity, platform services, and governance controls aligned to architectural standards
- Exchange Administration: Design, implement, administer, and support Microsoft Exchange Online within a Microsoft 365 environment.
- Identity & Access: Engineering and operation of Active Directory and Entra ID, including authentication, Conditional Access, privileged access, identity governance, and directory integration
- Cloud Security & Compliance: Implementation and maintenance of secure configurations, monitoring, logging, encryption, and policy enforcement across cloud and identity platforms
- Delivers and supports standardisation, automation, tooling, and consistency across cloud, workplace, and identity platforms
Key Accountabilities 1. Solution Engineering & Operation
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