Lead System Administrator

About the role

We are seeking a Lead System Administrator to join a global financial services organization in Singapore. This hands‑on role focuses on Microsoft messaging and cloud infrastructure, ensuring a secure, reliable environment for enterprise users.

Key responsibilities

• Administer on‑premises Microsoft Exchange (2019/Subscription Edition) and Exchange Online, handling day‑to‑day operations, mail flow, mailbox management and licensing.
• Plan and execute migrations from on‑premises Exchange to Exchange Online/Microsoft 365, including hybrid coexistence and cut‑over activities.
• Support messaging integration with Microsoft Entra ID and Azure, working with SSO, federation (OIDC, OAuth 2.0, SAML) and IAM teams.
• Maintain core Windows infrastructure: Windows Server, Active Directory, Group Policy, DNS, DHCP, and AD Connect.
• Participate in incident and change management, ensure security and audit readiness, and automate tasks with PowerShell.

Required profile

• Strong, hands‑on experience administering on‑premises Exchange (preferably 2019 or Subscription Edition).
• Proven track record planning and delivering migrations to Exchange Online/Microsoft 365.
• Experience supporting an enterprise IT environment and end‑users.
• Ability to work collaboratively, take ownership of operational issues and provide support outside regular hours when needed.

Required skills

• Microsoft Exchange Server (2019/Subscription Edition)
• Exchange Online & Microsoft 365
• Microsoft Entra ID, Azure, Azure Stack
• Windows Server, Active Directory, Group Policy, DNS, DHCP, AD Connect
• PowerShell scripting
• Identity protocols: OIDC, OAuth 2.0, SAML
• Conditional Access, Multi‑Factor Authentication, RBAC/PIM