Senior System Engineer Jobs in Ontario (NOW HIRING)

At OSL Retail Services, we believe people are the heart of everything we do, and it is an exciting time to be part of something special! Our momentum is growing, and is fueled by innovation, collaboration, and a shared entrepreneurial spirit that drives real results. Founded in 2012 in Mississauga, Ontario, OSL delivers customized sales solutions in retail, direct sales, and customer acquisition, all built on a foundation of integrity, respect, and passion. Our culture thrives on connection, purpose, and growth. If you’re looking for a place where your talents are valued, your ideas matter, and your career can grow, we’d love to meet you.

The Opportunity:

As Senior System Engineer, you will be instrumental in managing our corporate infrastructure, cybersecurity and cloud services. Your expertise will ensure the highest reliability and performance, supporting our commitment to delivering exceptional service to our clients and customers. This role involves working on complex projects, including evolving existing systems and implementing new technologies. It will be based out of our corporate office in Mississauga, Ontario.

Key Responsibilities:

• Oversee corporate network operations: Administer network infrastructure, firewalls, VPNs, and maintain robust network troubleshooting and security measures.
• Develop and maintain documentation: Prepare and update system configurations, mappings, process documentation, and problem management records.
• Supervise desktop and cloud infrastructure: Manage both on-premises and Azure cloud environments.
• Continually monitor OSL’s IT landscape: Maintain vigilant oversight of capacity and performance metrics.
• Support IT strategy and service improvement: Actively participate in tactical planning and contribute to the enhancement of all IT service deliveries.
• Administer application servers: Oversee a diverse environment comprising Windows, Linux, and Azure-based resources.
• Enforce security controls: Ensure the implementation of best-practice security measures across all systems.

Required Knowledge, Skills, and Abilities:

• Deep expertise in designing, operating, and securing enterprise network environments, including firewalls, switches, access points, VPN technologies, and MPLS or equivalent WAN solutions.
• Strong systems engineering background with advanced experience in automation, configuration management, and secure-by-design principles across network and infrastructure platforms.
• Demonstrated ability to lead the technical design and implementation of complex networking and security initiatives, balancing scalability, resiliency, and risk management.
• Advanced proficiency administering and troubleshooting both Windows and Linux environments, with the ability to diagnose and resolve issues across networking, systems, and applications.
• Extensive experience with scripting and automation using PowerShell, Bash, and/or Python to improve reliability, reduce manual effort, and enforce standards.
• Hands-on experience building and operating monitoring, observability, and alerting solutions using tools such as Zabbix, Azure Monitor, Prometheus, Grafana, Datadog, and centralized logging platforms (e.g., ELK, Loki, Graylog).
• Strong working knowledge of Microsoft Entra ID / Active Directory, identity federation, and access control models in hybrid and cloud-integrated environments.
• Proven ability to take full ownership of technical outcomes, including architecture decisions, implementation, documentation, and ongoing operational excellence.
• Excellent communication and stakeholder management skills, with the ability to translate complex technical concepts, risks, and trade-offs into clear business-facing language.
• Experience providing Tier3 operational support and participating in after-hours on-call rotations for critical infrastructure services.
• Solid understanding of ITIL practices (Incident, Change, and Problem Management), with experience improving operational processes and system stability over time.

What you’ve done:

• 5+ years experience supporting engineering enterprise environments across networking, security, Windows and Linux systems, and cloud platforms.
• Expert knowledge of core networking protocols and services, including TCP/IP, DNS, DHCP, routing, and VPN technologies (site-to-site and client-based).
• Strong experience with Fortinet firewalls and networking equipment; Fortinet certifications (e.g., NSE) are a strong asset.
• Proven experience designing and supporting cloud and hybrid networking solutions, with Microsoft Azure strongly preferred (AWS or GCP experience considered an asset).
• Hands-on experience delivering Infrastructure as Code using tools such as Terraform, Ansible, and/or Chef to provision and manage network and system resources.
• Working knowledge of database platforms such as Microsoft SQL Server and PostgreSQL, particularly as they relate to infrastructure, performance, and availability considerations.
• Experience implementing enterprise observability, monitoring, and alerting strategies using. platforms such as Azure Monitor, Prometheus, Datadog, and related tooling.

Working Conditions:

• Flexibility to work various schedules, including evenings and weekends, as required.

What’s in it for you:

• Competitive base salary: $100K-$115K plus bonus.
• Generous time off: Start with 3 weeks of vacation, plus extra flex days to recharge.
• Comprehensive benefits package: Includes medical, dental, vision, health spending account, and Teladoc virtual care.
• Retirement support: Company-sponsored savings plan to help build your financial future
• Career growth: Ongoing training, development, and programs to help you advance.
• Award-winning culture: Proud to be one of Canada’s Best Managed Companies for 8 years running - now a Platinum Club member.

The Interview Process:

• Stage 1: If your profile is a match, we will invite you for a first conversation with the recruiter.
• Stage 2: The next step is a in-person interview with the hiring manager.
• Stage 3: The final step is an in-person interview with the hiring manager and extended team members.

If this sounds like you and you’re excited to be a member of our team - please apply now. 

Disclaimer: As part of our recruitment process, we utilize artificial intelligence (AI)-based tools to assist with certain stages, including initial resume screening and skills-matching assessments. These tools are designed to help our hiring team identify candidates whose experience and qualifications align closely with the requirements of the role. Please note that all final hiring decisions are made by our recruitment team.  The preceding job description has been designed to indicate the general nature and level of work performed by employees within this job. It is not designed to contain or be interpreted as a comprehensive inventory of all duties, responsibilities and qualifications required of employees assigned to this job.  In compliance with Ontario’s Bill 190, we confirm that this posting represents a current existing vacancy within our organization.