IT/OT Senior Systems Administrator

KRISSILAS GROUP INC; Toronto; Hybrid; CAD 90,000 - 130,000; Full time

Job summary

KRISSILAS GROUP INC is seeking an IT/OT Senior Systems Administrator to design, secure, and modernize a hybrid on-premises and cloud infrastructure across corporate and operational sites.

You will ensure high availability and security for IT and OT systems, collaborating with internal teams and vendors to deliver reliable technology solutions and support modernization initiatives.

Qualifications

• 5+ years of enterprise systems administration or infrastructure experience.
• 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.
• Strong networking knowledge across TCP/IP, DNS, DHCP, VLANs, routing, switching and VPNs.
• PowerShell scripting and automation skills.
• Excellent troubleshooting, communication and problem-solving abilities.
• Collaborative, ownership-driven approach across IT and OT environments.

Responsibilities

• Design, administer, optimize and support a hybrid on-premises and cloud environment.
• Ensure high availability, security and reliability for IT and OT systems.
• Manage Windows Server, Active Directory, Entra ID, Microsoft 365 and Azure environments.
• Administer and optimize VMware and Hyper‑V virtualization, including capacity planning.
• Support enterprise networking (DNS, DHCP, VPN, VLANs) and connectivity.
• Manage backup, disaster recovery, business continuity and infrastructure monitoring.
• Provide Tier‑3 technical support and lead complex infrastructure troubleshooting.
• Partner with internal teams, vendors and MSPs to deliver reliable technology solutions.
• Contribute to cloud adoption, infrastructure modernization and automation initiatives.
• Provide occasional onsite support at corporate and operational locations.

Skills

Windows Server

Active Directory

Entra ID

Microsoft 365

Azure

VMware/Hyper‑V

PowerShell scripting

Networking (DNS/DHCP/VLANs/VPN)

Backup/DR/Monitoring

IT & OT collaboration

Tools

VMware

Hyper‑V

Azure

Microsoft 365

Entra ID

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.