Senior Systems Administrator

Primary Responsibility:

Serve as the senior technical escalation point for MIRATECH's US IT operations from our Tulsa, OK office, providing deep expertise in systems administration, network infrastructure and complex end-user issues that exceed the scope of the Level 1/2 help desk. The role acts as the resolver of last resort across US sites, partners with global IT teams on cross-region projects, infrastructure changes and security initiatives, and proactively improves the reliability, performance and security of core IT systems. By owning hard-to-solve incidents end-to-end and mentoring the help desk team, the Senior Systems Administrator keeps MIRATECH's US workforce productive and our infrastructure resilient.

What You'll Do:

The core responsibilities of this role include:

• Serve as the Level 3 escalation point for the US Help Desk team, taking ownership of complex incidents that cannot be resolved at Level 1 or Level 2.
• Administer and maintain core server infrastructure including Windows Server, Active Directory, DNS, DHCP, file and print services, Group Policy and virtualization platforms (Hyper-V).
• Design, configure, monitor and troubleshoot enterprise network infrastructure including switches, routers, firewalls, VPNs, and Wi-Fi across US sites. • Manage Microsoft 365, Azure / Entra ID, Intune and other cloud and SaaS platforms at an administrator level, including identity, access, MFA and conditional access policies.
• Support and harden endpoint security tooling (EDR / AV, MFA, patching and vulnerability remediation) and partner with security stakeholders on hardening initiatives.
• Lead root cause analysis for major incidents, document findings and drive permanent fixes through to completion.
• Plan and execute infrastructure changes, upgrades and migrations during scheduled maintenance windows, including out-of-hours work where needed.
• Participate in a shared on-call rotation for critical incidents impacting US offices and escalations from global teams.
• Partner with global IT teams on cross-region projects, standards and architecture decisions, and act as a senior point of escalation for international IT colleagues.
• Mentor Level 1 and Level 2 technicians, develop runbooks and contribute high-quality content to the knowledge base (e.g. IT Glue). • Other duties as assigned.

How to Qualify:

The minimum qualifications required to perform this role are:

• Education: Bachelor's degree in Information Technology, Computer Science or a related field, or equivalent professional experience.
• Experience: 7-10 years in IT support or systems administration, including demonstrable time at a Level 3 / senior escalation level supporting business-critical infrastructure.
• Technical Skills: Deep, hands-on expertise across Windows Server, Active Directory, Group Policy, Microsoft 365, Azure / Entra ID, enterprise networking (TCP/IP, routing and switching, VLANs, firewalls, VPN, Wi-Fi), endpoint management (Intune / MDM), virtualization (Hyper-V or VMware) and endpoint security (EDR, MFA, conditional access, patching).
• Communication Skills: Excellent written and verbal communication; able to translate complex technical issues for non-technical stakeholders, write clear runbooks and lead incident bridges with confidence.
• Organizational Skills: Ability to manage multiple priorities in a fast-paced environment, owning complex incidents end-to-end while balancing project work and mentoring of junior staff.
• Other: Willingness to participate in a shared on-call rotation and perform occasional after-hours work for scheduled maintenance windows.

What Sets You Apart:

Optional qualifications that would make a candidate especially strong:

• Industry certifications such as Cisco CCNA / CCNP, Microsoft AZ-104 / AZ-305 / MS-100, CompTIA Network+ / Security+, or ITIL Foundation.
• Scripting and automation experience (PowerShell, Bash, Python) and familiarity with infrastructure-as-code tooling (e.g. Terraform, Ansible).
• Experience supporting multi-site or global environments using RMM / PSA tooling (e.g. NinjaOne, ConnectWise Automate, ConnectWise Manage) and documentation platforms such as IT Glue.

What We Offer:

• Health, Dental & Vision Insurance
• Annual Bonus Program
• $350 Annual Wellness Credit
• Flexible Spending Account (FSA)
• 401k with match up to 5%