Mechanical Engineer

ABOUT MARIANA MINERALS

Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making.

THE ROLE

Mariana Minerals is looking for a highly motivated Mechanical Engineer to join our San Francisco Pilot Plant team. You will support the design, installation, and maintenance of first-of-its-kind refining processes for critical minerals. This position plays a critical role in bridging R&D and Operations, ensuring our equipment and work processes are robust, safe, cost-effective, and suitable for commercial production.

WHAT YOU'LL DO

• Drive design, fabrication, installation, modification, startup, and commissioning of new equipment and pilot plant systems.
• Troubleshoot mechanical issues and implement practical solutions to maintain safe, reliable, and efficient plant operations.
• Work closely with process engineers and R&D scientists to translate process requirements into equipment modifications, mechanical designs, and plant improvements.
• Create and maintain engineering documentation, including P&IDs, process and control narratives, equipment specifications, drawings, CAD models, and equipment manuals.
• Identify opportunities to improve equipment reliability, maintainability, and operational performance
• Support the development of software and to help drive rapid equipment design, plant reliability, and safe operation
• Travel to Mariana sites to support new projects, start-up/commissioning, and troubleshooting initiatives

WHAT YOU'LL BRING

• B.S., M.S., or PhD in Mechanical Engineering or a related field
• Experience in automated manufacturing, operations, process scale-up, or plant design in minerals processing, chemicals, specialty materials, oil & gas, or related industries
• Demonstrated experience driving equipment design, commissioning, operations, and reliability
• Ability to wear multiple hats and take on additional scope in areas such as process engineering, operations, maintenance, and project execution
• Strong troubleshooting and problem-solving skills in hands-on plant environments
• Strong commitment to Health, Safety, and Environmental compliance and mechanical integrity standards
• Excellent technical writing, communication, and teamwork skills
• Comfortable working in fast-paced environments and managing ambiguity

OUR CULTURE IS BUILT ON FOUR PRINCIPLES

• Everyone Gets Home Safe. We never put speed or cost ahead of people.
• Extreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions.
• Engineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale.
• Share Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.
• JOIN US AS WE BUILD THE FUTURE OF RESPONSIBLE MINERAL SOURCING AND SUPPLY!