Senior Systems Engineer - M365 Operations

OPTIMUM SOLUTIONS (SINGAPORE) PTE LTD; Singapore; On-site; SGD 120,000 - 180,000; Full time

Job summary

Optimum Solutions (Singapore) Pte Ltd is seeking a senior Microsoft 365 administrator to provide operational and technical support for the Microsoft 365 suite, ensuring availability, security and policy compliance across Entra ID, Exchange Online, SharePoint Online, Teams and OneDrive for Business.

You will operate independently in a large enterprise environment, with deep Identity and Access Management expertise, and a proven ability to resolve complex collaboration and messaging issues while

Qualifications

• Senior hands-on experience administering Microsoft 365 services (8–10 years).
• Must have worked in large enterprise environments.
• Strong AD and M365 background.
• Identity and Access Management with M365, AD, and Azure AD.
• Experience with Entra ID, Exchange Online, SharePoint Online, Teams, and OneDrive.
• Experience supporting large enterprise Microsoft 365 environments.
• Ability to operate independently with minimal supervision.

Responsibilities

• Operate, administer, and support account lifecycle management using in-house Account Provisioning System and on-prem AD servers.
• Manage configurations for mailboxes, distribution lists, shared mailboxes, Teams, and SharePoint Online sites.
• Configure and maintain MFA, role assignments, and service-level access controls.
• Troubleshoot complex collaboration, identity, and messaging issues across M365 services.
• Resolve incidents with minimal supervision and escalate to Microsoft Support when required.
• Maintain operational documentation, runbooks, and configuration records.
• Work closely with various departments to manage account lifecycle.

Skills

M365 Admin

Azure Entra ID

Active Directory

Exchange Online

SharePoint Online

Teams & OneDrive

MFA & access controls

Incident troubleshooting

Tools

Account Provisioning System

Job description

Role Purpose

Provide senior-level operational and technical support for Microsoft 365 collaboration, messaging, and identity services, ensuring availability, security, and compliance with organisational policies.

Key Responsibilities

• Operate, administer, and support account lifecycle management using in-house application (Account Provisioning System), on-premise Active Directory servers, Microsoft 365 services including Entra ID (Azure Active Directory), Exchange Online, SharePoint Online, Microsoft Teams, and OneDrive for Business
• Manage configurations for mailboxes, distribution lists, shared mailboxes, Teams, and SharePoint Online sites in accordance with approved standards
• Configure and maintain security-related settings such as MFA, role assignments, and service-level access controls within Microsoft 365
• Troubleshoot complex collaboration, identity, and messaging issues across Microsoft 365 services
• Resolve incidents with minimal supervision and elevate to Microsoft Support where required
• Maintain operational documentation, runbooks, and configuration records
• Work closely with various departments to manage account lifecycle

Required Skills & Experience

• Senior hands‑on experience administering Microsoft 365 services (Minimum 8-10 years)
• Must have worked in large enterprise environments
• Strong AD and M365 background
• Very strong knowledge on Identity and Access Management using M365, AD, and Azure AD
• Strong working knowledge of Entra ID, Exchange Online, SharePoint Online, Microsoft Teams, and OneDrive
• Experience supporting large enterprise Microsoft 365 environments
• Ability to operate independently with minimal supervision