Engineering Technician

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.

Mariana Minerals is looking for a highly motivated Engineering Technician to join the San Francisco Pilot Plant team. You will support the design, deployment, and operation of first-of-its-kind refining processes for critical minerals, while also supporting development of software for automated plant optimization. This position is highly hands‑on and will play a critical role in bridging R&D, Process Engineering, and Operations, ensuring processes are robust, safe, cost‑effective, and suitable for commercial production.

• Support bench‑top R&D, pilot‑scale experiments, technical evaluations, and other scale‑up trials
• Monitor, troubleshoot, and optimize equipment performance.
• Drive evaluations of recovery, throughput, product quality, and equipment reliability.
• Assist with equipment design, installation, commissioning, and modification
• Create SOPs, engineering drawings, and other process design documentation
• Train on all pilot plant operating steps and fill in when needed to help keep pilot plant running to plan

• Bachelor’s degree in engineering, materials science, or equivalent field
• 3+ years of hands‑on pilot plant, R&D scale‑up, or industrial operations experience
• Experience supporting experiments, process trials, or equipment testing
• Ability to collect quality data, document observations, and communicate results clearly
• Experience with process equipment design, procurement, setup, and troubleshooting
• Strong understanding of pH, inorganic chemistry, mass balance, fluid handling, and solid‑liquid separation
• Experience creating and maintaining SOPs, PFDs, P&IDs, and equipment/process design documentation

At Mariana Minerals, you’ll be part of a mission‑driven team reshaping the way critical minerals are sourced and supplied globally. You’ll have the autonomy to make big decisions, the tools to innovate, and a culture that values ownership, smart automation, and collaboration.

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.

Mariana is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. We do not discriminate on the basis of race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, veteran status, or any other protected status.