Senior System Engineer

Rajah & Tann Singapore LLP; Singapore; On-site; SGD 90,000 - 130,000; Full time

Job summary

Rajah & Tann Singapore LLP is seeking an experienced Systems Engineer to design, implement, and maintain secure, scalable IT infrastructure across on-premises and cloud environments, spanning Windows, Linux, Azure, and Microsoft 365.

You will work with IT and business teams on cloud migrations, security hardening, automation with PowerShell and Bash, and disaster recovery planning to ensure resilience and audit readiness.

Qualifications

• Bachelor’s degree in Computer Science, Information Systems, Engineering or related discipline.
• 5+ years in infrastructure engineering or related roles.
• 3+ years Windows Server administration (AD, DNS, GPO).
• 3+ years Linux administration (RHEL/Ubuntu).
• 3+ years Microsoft 365 administration (Exchange Online, SharePoint Online, Teams, Entra ID).
• Hands-on Azure services experience (VMs, VNets, NSGs, Load Balancers, Storage, Backup, Site Recovery).
• Networking fundamentals and enterprise network infrastructure experience.
• Experience with infrastructure security, patch management, CIS benchmarks, IAM.

Responsibilities

• Design, implement and maintain enterprise infrastructure across Windows and Linux.
• Deploy and manage Azure-based infrastructure including VMs, networking, and identity services.
• Administer Windows and Linux servers, patching, hardening, and lifecycle management.
• Configure and manage network infrastructure including firewalls, VPNs, and load balancers.
• Implement security controls and ensure audit readiness.
• Monitor health and performance, analyze incidents and perform RCA with permanent remediation.
• Develop automation scripts (PowerShell, Bash) to streamline provisioning and operations.
• Design and maintain backup and disaster recovery solutions.
• Collaborate with internal teams and vendors on infrastructure projects and migrations.

Skills

Infrastructure engineering

Automation scripting

Security best practices

Stakeholder communication

Team collaboration

Education

Bachelor’s degree in Computer Science, Information Systems, Engineering or related discipline

Tools

PowerShell

Bash

Azure Monitor

Azure Arc

Veeam

Palo Alto

Meraki

Active Directory

DNS

Group Policy

Job description

About the Role

We are seeking an experienced Systems Engineer to design, implement, and maintain secure, resilient, and scalable IT infrastructure across on-premises and cloud environments.

This role spans Windows and Linux systems engineering, Microsoft Azure cloud operations, Microsoft 365 administration, and enterprise network infrastructure, with a strong emphasis on security, reliability, automation, and audit readiness. You will collaborate closely with IT teams and business stakeholders to support ongoing transformation initiatives, including cloud migration, infrastructure modernization, and operational excellence.

Key Responsibilities

• Design, implement and maintain enterprise infrastructure across Windows and Linux environments, ensuring high availability, performance and operational stability.

• Deploy, configure, and manage Azure-based infrastructure, including virtual machines, networking, storage, and identity services, ensuring alignment with enterprise architecture and security standards.

• Administer and optimise Windows and Linux server environments, including patching, hardening, performance tuning, capacity planning, and lifecycle management.

• Configure and manage network infrastructure including firewalls, VPNs, load balancers, and routing to ensure secure and efficient connectivity across on-premises and cloud environments.

• Implement infrastructure security controls aligned with secure configuration baselines and best practices, ensuring compliance with organisational policies and audit requirements.

• Proactively monitor infrastructure health and performance, respond to incidents, and conduct thorough root cause analysis (RCA) with permanent remediation actions.

• Develop and maintain automation scripts and infrastructure tooling (e.g., PowerShell, Bash) to streamline provisioning, configuration management, monitoring, and operational workflows.

• Design, implement, and maintain backup and disaster recovery (DR) solutions, ensuring business continuity and alignment with recovery objectives.

• Work closely with internal teams and external vendors to support infrastructure projects, cloud migrations, system upgrades, and ongoing operations.

Requirements

• Bachelor’s degree in Computer Science, Information Systems, Engineering or any other related discipline

• Minimum 5 years of experience in infrastructure engineering, systems engineering, or infrastructure consulting roles.

• Minimum 3 years hands‑on experience administering Windows Server environments, including Active Directory, DNS, Group Policy, and virtualization platforms.

• Minimum 3 years of hands‑on experience administering Linux environments (Red Hat, Ubuntu, or equivalent enterprise distributions).

• Minimum 3 years of experience in Microsoft 365 administration, including Exchange Online, SharePoint Online, Teams, and Entra ID, with exposure to identity management, security, and compliance features.

• Hands‑on experience with Microsoft Azure services, including Virtual Machines, Virtual Networks, Network Security Groups (NSGs), Load Balancers, Azure Storage, Azure Backup, Site Recovery, and identity services (Microsoft Entra ID and Active Directory integration).

• Experience working on networking fundamentals, including TCP/IP, routing, switching, Wi‑Fi (Meraki), Firewalls (Palo Alto), VPNs, network segmentation, secure network design principles.

• Experience working on networking concepts and enterprise network infrastructure, including TCP/IP, routing, switching, VPNs, Wi‑Fi (Meraki), firewalls (Palo Alto), network segmentation, and secure network design principles.

• Experience implementing infrastructure security and hardening practices, including patch management, CIS benchmark alignment, vulnerability remediation, privileged access controls, and identity and access management.

• Experience working on automation and scripting on PowerShell, Bash, or equivalent.

• Familiarity with infrastructure monitoring tools (e.g., Azure Monitor / ARC, logs)

• Familiarity with backup and disaster recovery solutions (Azure Backup, Veeam)

• Enjoys analytical and troubleshooting work.

• Ability to clearly articulate technical concepts to stakeholders.

• Collaborative mindset with experience working across IT, security, and business teams.