IT/OT Senior Systems Administrator

Krissilas Group; Toronto; On-site; CAD 90,000 - 140,000; Full time

Job summary

Krissilas Group, a Canadian company with a global presence, is seeking an experienced IT/OT Senior Systems Administrator to design, secure, and modernize our hybrid on-premises and cloud infrastructure across corporate and operational sites.

You will manage Windows Server, AD, Entra ID, M365, Azure, VMware/Hyper-V, and core networking, with emphasis on patching, backups, DR, IAM controls, and Tier-3 support.

Qualifications

• 5+ years of enterprise systems administration or infrastructure experience.
• Strong hands-on expertise with Windows Server, Active Directory, Entra ID, VMware/Hyper-V and Microsoft 365.
• Experience with Azure, virtualization, storage, backup and disaster recovery.
• Solid networking knowledge across TCP/IP, DNS, DHCP, VLANs, routing, switching and VPNs.
• Strong PowerShell scripting and automation skills.
• Excellent troubleshooting, communication and problem-solving abilities.
• A collaborative, ownership-driven approach and the ability to work across IT and OT environments.

Responsibilities

• Design, administer, optimize hybrid on-prem and cloud environment.
• Manage Windows Server, AD, Entra ID, M365 and Azure.
• Administer VMware/Hyper-V, storage and capacity planning.
• Support networking, DNS, DHCP, VPN, VLANs and connectivity.
• Manage backup, disaster recovery, business continuity and monitoring.
• Support Exchange, SQL Server, Intune and enterprise apps.
• Implement patching, vulnerability remediation, security baselines and IAM controls.
• Provide Tier-3 technical support and lead complex infra troubleshooting.
• Partner with internal teams, vendors and MSPs to deliver reliable solutions.
• Contribute to cloud adoption, infrastructure modernization and automation initiatives.
• Occasional onsite support at corporate and operational locations.

Skills

Windows Server

Active Directory

Entra ID

Microsoft 365

Azure

VMware/Hyper-V

DNS/DHCP/VPN

PowerShell

Troubleshooting

IT/OT environments

Job description

Join a Global Leader. Help Build the Future of IT/OT Infrastructure.

Our client is a Canadian company with a global presence and a growing technology team. As their operations continue to expand, they are looking for an experiencedIT/OT SeniorSystems Administrator to play a key role in supporting, securing, and modernizing their technology infrastructure.

This is an opportunity to join a dynamic, collaborative environment where your expertise will directly contribute to the reliability, security, and evolution of critical IT and OT systems.

The Opportunity

You will design, administer, optimize, and support a hybrid on-premises and cloud environment, ensuring a highly available, secure infrastructure across corporate and operational sites.

Key areas of responsibility include:

• Manage Windows Server, Active Directory, Microsoft Entra ID, Microsoft 365 and Azure environments.
• Administer and optimize VMware and Hyper‑V virtualization, including servers, storage, and capacity planning.
• Support enterprise networking, DNS, DHCP, VPN, VLANs and connectivity.
• Manage backup, disaster recovery, business continuity and infrastructure monitoring.
• Support Exchange, SQL Server, Intune and enterprise applications.
• Implement patching, vulnerability remediation, security baselines and identity/access controls.
• Provide Tier‑3 technical support and lead complex infrastructure troubleshooting.
• Partner with internal teams, vendors and managed service providers to deliver reliable technology solutions.
• Contribute to cloud adoption, infrastructure modernization and automation initiatives.
• Provide occasional onsite support at corporate and operational locations.

What You Bring

• 5+ years of enterprise systems administration or infrastructure experience.
• Strong hands‑on expertise with Windows Server, Active Directory, Entra ID, VMware/Hyper‑V and Microsoft 365.
• Experience with Azure, virtualization, storage, backup and disaster recovery.
• Solid networking knowledge across TCP/IP, DNS, DHCP, VLANs, routing, switching and VPNs.
• Strong PowerShell scripting and automation skills.
• Excellent troubleshooting, communication and problem‑solving abilities.
• A collaborative, ownership‑driven approach and the ability to work across both IT and OT environments.

Assets: Linux administration, OT/HMI environments, Palo Alto, Cisco or HPE/Aruba technologies, and relevant Microsoft, VMware or Veeam certifications.

Why Join?

• Join a Canadian global leader with continued growth and investment in technology.
• Be part of a dynamic team working at the intersection of IT, OT, cloud and cybersecurity.
• Make a direct impact on critical infrastructure and operational excellence.
• Opportunity to contribute to modernization and transformation initiatives, not just day‑to‑day administration.
• Work alongside talented professionals in a collaborative and evolving environment.