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 RoleWe are hiring a Mechanical Engineering Intern to work on real, high-impact problems within the Pilot Plant Operations team in San Francisco. You will contribute directly to design, improvement, and optimization of benchtop pilot plant equipment, working closely with engineers and domain experts.
This role is designed to provide hands-on experience building and shipping solutions, not just supporting tasks.
What You’ll DoCreate 3D models, layout drawings, and other critical documentation for equipment in the lab and pilot plant
Build, test, and iterate on hands-on mechanical solutions to improve equipment performance, decrease equipment downtime, controls costs, and improve health & safety
Collaborate with engineering, management, and software engineering to build programs and applications for Mariana’s operations teams
Collaborate with cross-functional team members (engineering, operations, controls engineering, etc)
Present outcomes and learnings at the end of the internship
Currently pursuing or recently completed degree in mechanical engineering or a related field
Strong fundamentals in mechanical design documentation such as equipment specifications, layout drawings, piping schematics, and CAD models
Hands-on experience designing or supporting industrial equipment including pumps, piping systems, reactors, separators, filtration systems, and material handling equipment
Ability to design mechanical solutions, troubleshoot problems, and analyze complex datasets independently
Excellent technical writing, communication, and teamwork skills
Comfortable working in fast-paced environments, wearing multiple hats, and managing ambiguity
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.
Our culture is built on three principles:
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.
Skills Required
- Currently pursuing or recently completed degree in mechanical engineering or a related field
- Strong fundamentals in mechanical design documentation such as equipment specifications, layout drawings, piping schematics, and CAD models
- Hands-on experience designing or supporting industrial equipment including pumps, piping systems, reactors, separators, filtration systems, and material handling equipment
- Ability to design mechanical solutions, troubleshoot problems, and analyze complex datasets independently
- Excellent technical writing, communication, and teamwork skills
- Comfortable working in fast-paced environments, wearing multiple hats, and managing ambiguity
What We Do
Mariana Minerals is a software-first, vertically integrated minerals company focused on supplying critical materials for energy, AI, and defense technologies. It combines digital infrastructure with mineral project development to secure reliable and sustainable supply chains.
