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 Fabrication Technician 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. As part of a growing maintenance team, you’ll help build out our fabrication capabilities, getting creative with the resources we have and adapting to the unique demands of R&D builds. 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 the fabrication, installation, modification, startup, and commissioning of new equipment and pilot plant systems in San Francisco and other sites across the US - Troubleshoot and repair mechanical issues on plant equipment including pumps, valves, piping systems, filtration units, and other process equipment. - Read and interpret engineering drawings, P&IDs, and equipment manuals to support maintenance and installation work. - Safely perform maintenance activities following plant safety procedures including Lockout/Tagout (LOTO), hot work permitting, and confined space entry. - Utilize MarianaOS CMMS system to document equipment builds and troubleshooting Desired Qualifications - Associate degree, technical certificate, or equivalent hands-on experience in industrial fabrication, mechanical technology, millwright work, or related field. - 3+ years of experience building or supporting industrial equipment in the minerals processing, chemicals, specialty materials, oil & gas, biotech, or similar industries. - Hands-on experience fabricating, modifying, and/or constructing industrial equipment - Hands-on experience with troubleshooting tasks such as pump repair, valve replacement, and instrument troubleshooting - Familiarity with core plant safety practices including Lockout/Tagout (LOTO), hot work permits, confined space entry, and safe work permitting systems. - Ability to read and interpret engineering drawings such as P&IDs, equipment diagrams, and mechanical layouts. - Ability to travel occasionally (10-25%) of the time to other Mariana sites to support fabrication activities - Ability to climb stairs, stand for extended periods of time, and safely lift up to 50 lbs. 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!