Senior IT Systems & Infrastructure Engineer – Multi-Site

Mariana Minerals; San Francisco (CA); On-site; USD 120,000 - 180,000; Full time

Job summary

Mariana Minerals is seeking a Sr. Systems Administrator to own hands-on systems administration across corporate, field, and industrial sites.

You will implement infrastructure, manage authentication and access, and coordinate with HR and MSPs to deliver urgent needs while guiding long-term IT direction. This builder-focused role emphasizes establishing device management, DR planning, security controls, and change processes.

Qualifications

• 5+ years in systems and network administration with end-to-end ownership of infrastructure projects.
• Hands-on experience with Microsoft 365 and Entra ID, including centralized authentication and SSO.
• Strong networking fundamentals — VLANs/segmentation, firewalls, VPNs, wireless, routing/switching.
• Scripting for administration and automation.
• Experience managing organization-level software/service licensing, including renewals and vendor coordination.
• Track record of building processes, systems, or tools from scratch.
• Experience coordinating or overseeing managed service providers or outside consultants.
• Preferred: mining/OT-adjacent environments, NIST SP 800-171/CMMC/ISO 27001, and Apple/Mac/Ubiquiti familiarity.
• This role requires ~25% travel to 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

SharePoint

PowerShell

Licensing management

MS 365 Admin Center

IT security

Education

Bachelor's degree in Information Technology or related field

Tools

PowerShell

SharePoint governance

Entra ID

MS 365 Admin Center

Job description

Mariana Minerals is seeking a Sr. Systems Administrator to own hands-on systems administration across corporate, field, and industrial sites.

You will implement infrastructure, manage authentication and access, and coordinate with HR and MSPs to deliver urgent needs while guiding long-term IT direction. This builder-focused role emphasizes establishing device management, DR planning, security controls, and change processes.