Senior Systems Engineer

Senior Systems Engineer

Location:

London

Job Family:
Systems Administration

Wellington Management is seeking a Senior Directory, M365 & Server Administrator to support and operate the firm’s core identity, collaboration, and Windows infrastructure platforms, including Active Directory, Microsoft 365, Windows Server, and VMware. This is a domain admin level role designed to provide deep technical support and operational continuity for these critical services outside of US business hours, while remaining fully embedded with US based engineering and operations teams.

The role will be based in London to ensure meaningful daily overlap with US teams and to enable close collaboration, shared ownership, and consistent engineering standards—rather than operating as a detached regional support function.

This role exists to strengthen the resilience, stability, and responsiveness of Wellington’s core identity and infrastructure platforms. You will work closely with senior engineers and architects across two closely aligned domains:

• Active Directory, Windows Server, and VMware
• Microsoft 365 operations, engineering, and architecture

Rather than being siloed, this role is intended to be deeply embedded in these teams—sharing responsibility for operational health, incident response, and continuous improvement of platforms that are critical to the firm. This is an excellent opportunity for a senior engineer who enjoys hands on technical ownership, complex troubleshooting, and working across identity, server, virtualization, and cloud collaboration technologies.

• Provide senior level operational support for:
  Active Directory (on prem and hybrid), Windows Server platforms, VMware virtualization environments, Microsoft 365 (identity, collaboration, and core services).
• Operate with domain administrator level access and responsibility, following established security and change controls.
• Ensure the stability, availability, and performance of core directory and server services during non US hours.
• Support and maintain Active Directory forests, domains, trusts, and replication.
• Troubleshoot complex AD issues including authentication failures, GPO processing, DNS dependencies, and hybrid identity scenarios.
• Support identity integrations with Microsoft Entra  downstream systems.
• Provide operational support for Microsoft 365 services, including identity related components and tenant configuration.
• Partner with M365 engineering and architecture teams to support changes, deployments, and incident response.
• Assist with troubleshooting cross platform issues spanning on prem AD, Entra , and M365 services.
• Support Windows Server operating systems and associated services.
• Assist with VMware platform operations, troubleshooting VM level and host level issues as required.
• Work closely with platform owners to maintain consistent standards and operational hygiene.
• Act as a senior escalation point during non US hours for incidents affecting directory, server, virtualization, or M365 platforms.
• Perform deep technical troubleshooting and root cause analysis.
• Contribute to post incident reviews and drive corrective and preventative actions.
• Work closely with US based engineers to ensure seamless handover, shared context, and consistent decision making.
• Participate in team rituals, operational reviews, and engineering discussions to remain aligned and embedded.
• Contribute to shared documentation, runbooks, and operational standards.
• Identify recurring issues, operational gaps, or manual processes and propose improvements.
• Support automation, standardization, and modernization efforts across AD, server, and M365 platforms.
• Maintain accurate documentation for configurations, procedures, and operational knowledge.

• Strong hands on experience administering Active Directory in a complex enterprise environment.
• Solid experience with Windows Server platforms.
• Working experience supporting VMware environments.
• Experience operating and supporting Microsoft 365 in an enterprise context.
• Proven ability to troubleshoot complex, cross platform issues involving identity, servers, virtualization, and cloud services.
• Comfortable…