Senior Systems Administrator - M365 & Infrastructure

Position SummaryConstellation HomeBuilder Systems is seeking a Senior Systems Administrator / M365 & Infrastructure Administrator to join our Information Technology team in Markham, Ontario.
This role will be responsible for the administration, security, governance, and strategic operation of our Microsoft 365 environment, Microsoft Entra ID platform, endpoint management systems, and collaboration technologies. The position will own technology services and responsibilities transitioning from shared corporate IT services as part of our integration with Jonas.
The successful candidate will serve as a senior technical resource responsible for identity and access management, Microsoft 365 administration, endpoint management, collaboration platforms, security governance, and infrastructure support. This individual will work closely with leadership, business stakeholders, and external vendors to ensure secure, reliable, and scalable technology services across the organization.
Primary ResponsibilitiesIdentity & Access Management
Administer and maintain Microsoft Entra ID
Manage user provisioning, deprovisioning, and lifecycle management
Configure and maintain Single Sign-On (SSO) integrations
Design and administer Conditional Access policies
Manage Multi-Factor Authentication (MFA) technologies
Administer external collaboration and B2B access
Conduct identity governance reviews and access certifications
Manage Microsoft licensing and group-based assignments
Maintain role-based access controls and security standards
Microsoft 365 Administration
Administer Microsoft 365 services including:
Exchange Online
Teams
SharePoint Online
OneDrive
Power Platform
Power BI
Manage retention and compliance policies
Configure and maintain mail flow and transport rules
Administer SPF, DKIM, and DMARC configurations
Implement and maintain Microsoft security controls
Support tenant governance and security best practices
Monitor service health and platform performance
Evaluate and implement new Microsoft 365 capabilities
Endpoint Management
Administer Microsoft Intune
Manage Windows Autopilot deployments
Develop and maintain device compliance policies
Manage application deployment and lifecycle management
Oversee workstation configuration standards
Manage endpoint patching and security updates
Support remote workforce technologies
Voice & Collaboration
Administer Microsoft Teams Phone
Support TouchPoint and related communication systems
Troubleshoot voice and collaboration issues
Coordinate with telecom and technology vendors
Manage call routing, auto attendants, and user provisioning
Ensure reliable collaboration services across the organization
Infrastructure & Security
Support core Windows infrastructure services
Participate in infrastructure modernization initiatives
Assist with cloud and hybrid infrastructure administration
Maintain security baselines and operational standards
Participate in security investigations and remediation efforts
Create and maintain system documentation, procedures, and standards
Participate in disaster recovery and business continuity planning
QualificationsRequired
7+ years of IT infrastructure and systems administration experience
5+ years administering Microsoft 365 environments
Strong experience with Microsoft Entra ID
Experience implementing and supporting SSO and Conditional Access
Experience with Exchange Online, SharePoint Online, and Teams
Experience administering Microsoft Intune and Windows Autopilot
Strong understanding of Microsoft licensing and tenant governance
Experience supporting cybersecurity and compliance initiatives
Strong troubleshooting, analytical, and problem‑solving skills
Excellent written and verbal communication skills
Preferred
Microsoft certifications such as:
Microsoft Certified: Identity and Access Administrator
Microsoft Certified: Enterprise Administrator Expert
Microsoft Certified: Security Administrator Associate
Microsoft Certified: Endpoint Administrator Associate
Experience with Teams Phone
Experience with Power BI administration
Experience with Palo Alto Networks security solutions
Experience supporting mergers, acquisitions, or tenant migrations
Experience working in SaaS or software organizations
Knowledge of Azure services and cloud administration
Success MeasuresThe successful candidate will:
Maintain a secure and compliant Microsoft 365 environment
Ensure timely onboarding and offboarding processes
Maintain high endpoint compliance and patching standards
Deliver reliable collaboration and communication services
Improve operational efficiency through automation and standardization
Maintain accurate documentation and governance processes
Successfully assume and operate services transitioning from shared corporate IT functions
Salary Range (Ontario & BC Only):The estimated base salary range for this role is CAD$90,000.00 - CAD$110,000.00 per year. We include salary ranges in job postings only where required by applicable pay transparency laws, based on the jurisdictions in which the role may be performed. The posted range is a good faith estimate and reflects factors that are subject to change. Final offer amounts may vary based on job-related factors, including work location, candidate experience and expertise, and other relevant considerations.
We recognize the value and importance of diversity and inclusion in our communities and in the workplace.
We celebrate diversity and one of our goals as an employer is to create an inclusive work environment for all employees.
We are an equal opportunity employer and do not discriminate against any employee or applicant because of race, religion, sex, sexual orientation including gender identity or expression, pregnancy, national origin, age, marital status, veteran status, disability status, or any other category or characteristic protected by law.
Applicants with disabilities who would like to require a reasonable accommodation related to any part of the application process may contact us at View email address on ca.hrm.tc.
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