Senior Systems & Network Administrator — Build IT/OT Infra

Mariana Minerals; Houston (TX); On-site; USD 130,000 - 200,000; Full time

Job summary

Mariana Minerals is seeking a Senior Systems Administrator to own hands-on systems, infrastructure, and user support across corporate, field, and industrial sites, freeing the Senior IT Manager to focus on architecture, budget, and strategy.

This builder-oriented role will help establish core capabilities in authentication, backup, and change management across a live mine, greenfield construction, and pilot facilities.

Qualifications

• 5+ years in systems and network administration with end-to-end ownership of infrastructure projects
• 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.

Responsibilities

• 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

Skills

Microsoft 365

Entra ID

PowerShell

Networking

Automation scripting

Infrastructure ownership

Vendor coordination

Documentation & training

Tools

SharePoint Admin

MS 365 Admin Center

Networking hardware

Job description

Mariana Minerals is seeking a Senior Systems Administrator to own hands-on systems, infrastructure, and user support across corporate, field, and industrial sites, freeing the Senior IT Manager to focus on architecture, budget, and strategy.

This builder-oriented role will help establish core capabilities in authentication, backup, and change management across a live mine, greenfield construction, and pilot facilities.