Senior IT Engineer

Third-Octet; Mississauga; On-site; CAD 80,000 - 99,000; Full time

Job summary

Third Octet in Mississauga is seeking an experienced Senior Support Architect to own complex Microsoft environments for multiple clients. You will drive end-to-end problem resolution, design standards, and keep customer environments operable and compliant.

You will lead migrations and new onboarding, implement Workplace OS layers, validate operability, mentor Tier 2 analysts, and collaborate with our Architect. The role blends incident response with project delivery and automation.

Qualifications

• Five or more years supporting and engineering Microsoft environments in a managed services or multi-customer setting.
• Own complex problems end to end and execute changes in production without incident.
• Strong capability to mentor and develop Tier 2 analysts.
• Clear, uncondescending plain-language communication with customers and team.

Responsibilities

• Act as the terminal operational escalation point for the Services team.
• Lead migrations, server and cloud transitions, and new customer onboardings.
• Validate that builds can be operated by the team and hand over properly.
• Run post-incident reviews that drive standards and automation.

Skills

Problem solving under pressure

Ownership of complex problems

Mentoring Tier 2 analysts

Plain-language communication

Tools

Microsoft 365

Exchange Online

Teams

SharePoint

Intune

Azure AD / Entra ID

Job description

The role

You are where things stop being stuck.

When our Senior Support Analysts cannot resolve something, it comes to you — and when you cannot resolve it, the question is no longer "who troubleshoots better," it is "what should the standard be." That is a design question for our Architect. Everything short of it is yours.

You are also the person who keeps our customer environments operable and conformant to standard: correcting drift, executing the complex changes, and — importantly — holding the authority to stop something that would leave the team supporting a mess.

That halt authority is real here. If you can see that a deliverable will generate six months of support pain, we want you to say so and stop it.

What you will do

Keeping things running

• Act as the terminal operational escalation point for the Services team
• Take technical command during major incidents: direct diagnosis, decide actions, keep leadership informed
• Execute complex change beyond established standards, safely, with rollback planned
• Remediate environments back to standard and keep them there
• Run post-incident reviews that actually change something — a standard, a runbook, an automation
• Develop our Tier 2 analysts deliberately, not incidentally

Delivering change

(roughly 40–50% of your time, with a dedicated Implementation Engineer seat planned as this work grows)

• Lead migrations, server and cloud transitions, and new customer onboardings
• Implement our Workplace OS layers to defined standard
• Validate that what gets built can be operated by the team, and hand it over properly

What you bring

Experience

• Five or more years supporting and engineering Microsoft environments, with real time in a managed services or multi-customer setting
• A track record of owning complex problems end to end, and of executing change in production without incident

Technical depth

• Microsoft 365 in depth: Exchange Online, Teams, SharePoint, Intune, Defender, Purview fundamentals
• Entra ID and Active Directory in depth — hybrid identity, authentication flows, Conditional Access
• Windows Server: AD, Group Policy, DNS, DHCP, file services, certificates
• Azure infrastructure: virtual machines, networking, storage, backup, Site Recovery, governance and cost
• Security in practice: MFA, Conditional Access, endpoint protection, patch and vulnerability management, Zero Trust, CIS familiarity
• Networking to a genuine troubleshooting standard. Cisco Meraki and Barracuda are directly relevant.
• PowerShell for administration and automation
• Backup, continuity, and DR — designing it and proving it works
• Valued certifications: Microsoft endpoint and administrator paths, the SC series, AZ-104 / AZ-305 / AZ-500

How you work

• Diagnostic rigour under pressure. Staying systematic when a customer is down and everyone is watching.
• Design judgement with standards deference. You know what good looks like and you still choose the standard over your own preference. That combination is rarer than raw skill and matters more to us.
• Risk calibration. Blast radius, rollback, and the discipline to stop.
• Teaching by default. You leave the team more capable than you found it.
• Plain-language translation. Explaining technical reality without condescension and without false comfort.
• Interest in automation. You do not have to be a developer. You do have to notice repetition and want it gone.

Why this role, here, now

We are honest about our situation: this seat is currently open, and its absence is being felt. That means two things for you. The work is needed and you will see your impact immediately. And you are joining a team that has just redesigned how it operates specifically so that this role is not the impossible everything-seat it can become elsewhere — escalation and project delivery are explicitly bounded, and a dedicated implementation seat is planned as that work grows.

Where it goes

Three capability bands within the tier, with compensation attached. From here: Architect, via standards and design contribution; Implementation Engineer, if delivery is your preference; or depth in seat, which is a legitimate and well-compensated answer. You will have a development plan, technical direction from our Architect, and protected time to grow.

What we offer

• Salary range: $80,000 – $99,000
• Personally tailored benefits - health, vision, dental, and paramedical
• Flexibility in how, when, and where you work across a 4.5-day workweek, with a vacation policy well above standard
• Focus windows that protect deep, uninterrupted work
• Broad exposure to technology through client engagements and lab environments
• Funded lifelong learning: an immersive education platform, vendor training, and soft-skills development
• Wellness support, including access to the employee wellness platform and a wellness allowance
• A defined career framework with development plans, capability bands, and protected development time
• An open voice in shaping the direction of the company, with leadership that serves your best interest
• Work. Life. Balance.

About Third Octet

We are a Canadian managed IT services provider, working since 2007 with small and mid-sized businesses — typically 25 to 150 employees — across the Greater Toronto Area and beyond. Our Workplace Suite is built on Microsoft 365, Microsoft Azure, Cisco Meraki, Barracuda, and Lenovo, and we are expanding it into Workplace OS: a deliberate operating model that layers shared visibility, governed automation, insights, and AI onto a secure, standardized foundation.

We are a small team supporting a growing base of customers, which means the work is real, the ownership is genuine, and what you build actually gets used.

How we screen

We use automated tools to help sort and shortlist applications. Every candidate who reaches the shortlist is reviewed by a person before any decision is made.

This posting is for an existing vacancy.