Sr. Systems Administrator

The Role

We are hiring a Sr. Systems Administrator to take primary ownership of hands-on systems administration, infrastructure implementation, and day-to-day user support across Mariana's corporate, field, and industrial sites, freeing the Senior IT Manager to focus on architecture, budget, and cross-organizational strategy.

This is a foundational, builder-oriented role rather than a purely operational one. Core capabilities such as device management, centralized authentication, backup and disaster recovery, incident response, and change management are still being established, and this person will help build them, not just run them. Because Mariana operates a live mine, a greenfield construction site, and growing pilot facilities at the same time, the role requires close coordination with Controls/OT engineering, Software Engineering, HR, managed service providers, and on-site stakeholders to deliver urgent requirements while ensuring they support longer-term infrastructure direction.

What You'll Do

• Administer Microsoft 365, Entra ID, and centralized authentication/SSO across corporate and field sites
• Own the technical layer of SharePoint (permissions, architecture, governance) and manage user access, device provisioning, and onboarding/offboarding with HR.
• Maintain software and SaaS license management, including renewals, entitlements, and cost optimization.
• Establish end-to-end hardware lifecycle management — procurement, provisioning, tracking, and retirement — across offices, pilot facilities, and field sites.
• Configure and support routers, switches, firewalls, VPNs, and wireless networks across a multi-site environment, and drive network monitoring, segmentation, and IT/OT boundary improvements.
• Build and document backup/disaster recovery plans, security controls, vulnerability management, and a formal incident response and change management process.
• Coordinate and hold accountable managed service providers and consultants
• Serve as the primary escalation point for complex user and site support issues, and develop help desk process, documentation, and SLAs.
• Mentor junior IT staff and build documentation/training that grows the team's overall technical depth.

Desired Qualifications

• 5+ years in systems and network administration with end-to-end ownership of infrastructure projects, not just ticket-based support.
• Deep hands-on experience with Microsoft 365 and Entra ID, including centralized authentication and SSO configuration.
• Strong networking fundamentals — VLANs/segmentation, firewalls, VPNs, wireless, routing/switching — with direct enterprise hardware experience.
• Working proficiency in PowerShell or similar scripting for administration and automation.
• Experience managing organization-level software/service licensing, including renewals and vendor coordination.
• A track record of building processes, systems, or tools from scratch, and comfort operating with incomplete documentation and ambiguity.
• Experience coordinating or overseeing managed service providers or outside consultants.
• Preferred: experience in industrial/mining/OT-adjacent environments, familiarity with NIST SP 800-171/CMMC/ISO 27001, and experience with Apple/Mac devices and Ubiquiti networking.
• This role requires approximately 25% travel to Mariana’s other offices and project sites.