Assistant Manager, IT Infrastructure & Cybersecurity

cla se asia holdings pte. ltd.; Singapore; On-site; SGD 70,000 - 90,000; Full time

Job summary

cla se asia holdings pte. ltd. is seeking an experienced Assistant Manager, IT Infrastructure & Cybersecurity to strengthen our IT environment in Singapore.

You will manage core systems, improve security controls and contribute to infrastructure and cybersecurity projects. The role demands hands-on expertise with Active Directory, Windows Server, Microsoft 365 and certificate management, plus how to secure endpoints and patch systems.

Qualifications

• Degree or diploma in IT, cybersecurity, CS or related field.
• 6–10 years of relevant IT infra/cybersecurity experience.
• Hands-on with Active Directory, Windows Server, DNS/DHCP and MS 365.
• Experience with certificate management and security controls.

Responsibilities

• Manage and support AD, user access, Group Policy and MS 365.
• Administer Windows Server, DNS, DHCP, file services, backups.
• Manage SSL/TLS certificates and CA services.
• Coordinate cybersecurity updates, patching, endpoint security and hardening.
• Monitor servers for reliability, performance and security.
• Troubleshoot infrastructure, access, application and security issues.
• Maintain IT documentation and system records.
• Automate repetitive tasks with PowerShell or similar tools.
• Support IT infra, cybersecurity, audit and compliance projects.
• Provide guidance and escalation support to junior IT team members.

Skills

Leadership & mentoring

Troubleshooting & problem solving

Clear communication

Stakeholder management

Education

Diploma or Degree in Information Technology, Cybersecurity, Computer Science or related field

Tools

Active Directory

Group Policy

Windows Server

DNS

DHCP

Microsoft 365

Certificate Authority

SSL/TLS certificates

PowerShell

Endpoint security

Job description

Job Description

We are looking for a hands-on Assistant Manager, IT Infrastructure & Cybersecurity to support and strengthen our IT infrastructure and cybersecurity operations.

In this role, you will have the opportunity to manage key IT systems, improve security controls and contribute to infrastructure and cybersecurity projects.

Key Responsibilities

• Manage and support Active Directory, user access, Group Policy and Microsoft 365.

• Administer Windows Servers, DNS, DHCP, file services, backups and related infrastructure.

• Manage SSL/TLS certificates and Certificate Authority services, including renewals and expiry monitoring.

• Coordinate cybersecurity updates, patching, endpoint security and system hardening.

• Monitor servers and systems to ensure reliability, performance and security.

• Troubleshoot infrastructure, access, application and security-related issues.

• Maintain IT documentation, procedures and system records.

• Automate repetitive IT administration tasks using PowerShell or similar tools where possible.

• Support IT infrastructure, cybersecurity, audit and compliance projects.

• Provide guidance and escalation support to junior IT team members.

Job Requirements

• Diploma or Degree in Information Technology, Cybersecurity, Computer Science or related field.

• Preferably 6–10 years of relevant experience in IT infrastructure, system administration or cybersecurity.

• Good hands-on knowledge of:

  • Active Directory & Group Policy

  • Windows Server

  • DNS & DHCP

  • Microsoft 365

  • Server and infrastructure administration

• Experience with Certificate Authority, SSL/TLS certificates or certificate management.

• Good understanding of cybersecurity, patch management, endpoint protection and access controls.

• PowerShell or scripting knowledge will be an advantage.

• Relevant Microsoft, networking or cybersecurity certifications will be an advantage.

• Good troubleshooting and problem-solving skills.

• Able to communicate technical matters clearly and work well with different stakeholders.

• Proactive, organised and comfortable taking ownership of IT issues and projects.

If you enjoy hands-on IT work, solving technical challenges and improving the security and reliability of systems, we would love to hear from you.