Senior 24x7 Mission-Critical Systems Manager

SCIENTE; Singapore; On-site; SGD 120,000 - 180,000; Full time

Job summary

SCIENTE is seeking an experienced System Manager to oversee a 24x7 mission-critical infrastructure, leading a team of system engineers to ensure availability and resilience. You will drive incident response, patching, security hardening, and disaster recovery, collaborating with SDM to deliver reliable IT services and continuous improvement across on-prem environments.

The role requires strong leadership, deep Windows and VMware expertise, and coordination with vendors during after-hours

Qualifications

• Degree/diploma in CS/IT/Computer Engineering or related field.
• 6 years of enterprise infrastructure experience with 3 years leading a team.
• 3 years of O&M experience for critical systems.
• Strong hands-on with Windows Server 2019+/Windows 11, Active Directory, GPO, PKI, and SSL/TLS management.
• VMware experience: ESXi, vCenter, vSAN.
• WSUS Offline and manual WSUS catalogue imports.
• SQL Server, endpoint security, cybersecurity technologies, and backup/restore.
• Experience troubleshooting 24x7 mission-critical on-prem environments.
• Willingness to support after-hours deployments, maintenance windows, and on-call duties.

Responsibilities

• Lead day-to-day operations of a 24x7 mission-critical system with engineers.
• Manage system availability, performance, security, and readiness.
• Coordinate maintenance, patching, upgrades with SDM.
• Lead incident response, root cause analysis, recovery with SDM.
• Review deployment plans, impact assessments, risk, and rollback strategies.
• Oversee infrastructure lifecycle: servers, virtualization, network, and upgrades.
• Ensure cybersecurity, backup, DR, and configuration management compliance.
• Identify risks and single points of failure; implement mitigations.
• Provide technical leadership and mentoring to the operations team.
• Engage stakeholders, customers, and vendors on service delivery.

Skills

Leadership

Incident management

24x7 operations

Cybersecurity

Disaster recovery

Patch management

Stakeholder communication

Troubleshooting

Education

Degree/Diploma in CS/IT/Computer Engineering

Tools

VMware ESXi

vCenter

vSAN

WSUS Offline

Windows Server 2019+

Active Directory

GPO

PKI

SSL/TLS certificates

SQL Server

Endpoint security (Trellix/SEP)

Backup/Restore solutions

Job description

SCIENTE is seeking an experienced System Manager to oversee a 24x7 mission-critical infrastructure, leading a team of system engineers to ensure availability and resilience. You will drive incident response, patching, security hardening, and disaster recovery, collaborating with SDM to deliver reliable IT services and continuous improvement across on-prem environments.

The role requires strong leadership, deep Windows and VMware expertise, and coordination with vendors during after-hours