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: 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% #J-18808-Ljbffr Miratechcorp