Senior Windows & AD Engineer — Security & Domain Services

PERSOL SINGAPORE PTE. LTD.; Singapore; On-site; SGD 180,000 - 240,000; Full time

Job summary

PERSOL Singapore Pte Ltd is seeking a Senior Windows Infrastructure Engineer to lead security, vulnerability remediation and OS hardening across a large enterprise server estate. The role focuses on AD and Windows Server platforms, with hands-on responsibility for legacy and end-of-life environments.

You will provide L4/Principal engineering guidance for AD DS, GPO, DNS, DHCP and related services, and collaborate with cross-functional teams to design, implement and enforce security baselines and

Qualifications

• 10+ years of hands-on Windows Infrastructure and AD engineering experience.
• Experience at Principal Engineer, L4 Engineer, Technical Lead, or Windows/AD SME level.
• Deep expertise in Windows Server and Microsoft Active Directory.
• Strong experience in server security, vulnerability remediation and Windows OS hardening.
• Proven experience supporting legacy or end-of-life Windows environments.
• Knowledge of AD DS, GPO, DNS, DHCP, Domain Controllers, replication, trusts, Kerberos, and LDAP/LDAPS.

Responsibilities

• Lead Windows Server security, vulnerability remediation and OS hardening across a large enterprise server estate.
• Assess, prioritize and remediate security vulnerabilities across ~1,500 legacy Windows servers/systems.
• Analyse vulnerability findings and determine remediation, configuration changes, patches, upgrades or mitigating controls.
• Implement and maintain Windows security baselines, OS hardening standards and configuration controls.
• Provide Principal/L4-level engineering expertise for Microsoft Active Directory and Windows Server infrastructure.
• Manage and troubleshoot Active Directory Domain Services (AD DS), Domain Controllers, Group Policy (GPO), DNS and DHCP.

Skills

Windows Server

Active Directory

Server security

Vulnerability remediation

OS hardening

GPO

DNS

DHCP

Domain Controllers

Kerberos

Job description

PERSOL Singapore Pte Ltd is seeking a Senior Windows Infrastructure Engineer to lead security, vulnerability remediation and OS hardening across a large enterprise server estate. The role focuses on AD and Windows Server platforms, with hands-on responsibility for legacy and end-of-life environments.

You will provide L4/Principal engineering guidance for AD DS, GPO, DNS, DHCP and related services, and collaborate with cross-functional teams to design, implement and enforce security baselines and