---
title: 'Staff Mechanical Engineer at Mariana Minerals'
canonical: 'https://feeny.ai/job/staff-mechanical-engineer-mariana-minerals-houston-9pbk0g78xp4t'
type: 'job'
last_seen: '2026-10-16'
---

# Staff Mechanical Engineer at Mariana Minerals

- **Company:** Mariana Minerals
- **Location:** Houston, TX
- **Compensation:** $140k–$175k
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-07-29
- **Last confirmed live:** 2026-10-16
- **Apply:** https://jobs.ashbyhq.com/marianaminerals/c59fd9e0-27b9-4125-bcfc-40569938359e

## Job description

## 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 seeking a highly motivated Staff Mechanical Engineer to support our next-generation minerals processing pilot plant in Houston. You will lead the design, integration, and deployment of pilot-scale mechanical systems and processing equipment used to demonstrate and scale innovative refining technologies for critical minerals. This role is highly hands-on and will play a key role in building and maintaining a first-of-its-kind pilot plant. You will work closely with process engineers, technicians, and cross-functional teams to design, install, commission, and improve pilot-scale equipment while ensuring systems are reliable, safe, and scalable to commercial production.

## What You’ll Do

- Design, specify, and deploy mechanical systems and equipment for pilot-scale mineral processing operations
- Work closely with process engineers to translate process requirements into practical mechanical and plant designs
- Support installation, troubleshooting, and maintenance of pilot plant equipment including pumps, piping systems, reactors, separators, filtration systems, and material handling equipment
- Develop and maintain mechanical design documentation including equipment specifications, layout drawings, piping schematics, and CAD models
- Identify opportunities to improve equipment reliability, maintainability, and operational performance
- Coordinate with vendors, fabricators, and contractors during equipment procurement and installation
- Support safe plant operations by contributing to hazard reviews, equipment safety design, and mechanical integrity programs

Desired Qualifications

- B.S., M.S., or PhD in Mechanical Engineering or a related field
- 9+ years of experience in 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
- Experience designing and maintaining furnaces, pumps and fluid handling systems, pressure vessels and reactors, piping systems and valves, filtration and separation equipment, and materials handling systems
- Ability to work closely with cross-functional teams including process engineering, operations, 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, wearing multiple hats, 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!

## About Mariana Minerals

## Company Overview
- **One-liner**: Mariana Minerals is a software-first, vertically integrated minerals company focused on supplying the minerals critical to modern energy, AI, and defense technologies.
- **Entity Type**: Private (Series A, $85M funding in July 2025)
- **Headquarters**: San Francisco, California, United States
- **Founded**: Not publicly available
- **Founders**: Turner Caldwell (Co-Founder & CEO)

## Core Business
- **Primary industry**: Metal Ore Mining / Critical Minerals
- **Target customers**: B2B – energy, AI, and defense supply chains (including downstream manufacturers and government entities)
- **Mission or purpose**: "Create a future of critical mineral abundance" by reimagining the global minerals supply chain with software, automation, and data-driven decision making.

## Products & Services
- **Copper One (formerly Lisbon Valley Copper Mine)**: World’s first autonomous mine, located in Utah. Produces copper using integrated automation and software control. Restarted production in April 2026.
- **Lithium One**: Lithium project (on the roadmap or early development).
- **Other mineral projects**: Graphite, Uranium, Rare Earth Metals, Cobalt, Nickel, Aluminium – at various stages (stealth or roadmap).
- **CapitalProjectOS**: Internal software platform for capital project management (mentioned in leadership bio).
- **Technology Stack**: React, dbt, TypeScript, Python, TensorFlow, PyTorch, microservices, SCADA, Autodesk, and many others – indicating a strong software engineering backbone.

## Market Standing
- **Valuation/Market Cap**: Not disclosed (private company)
- **Key Metric**: Total funding – $85M Series A (July 2025, 1 investor)
- **Notable Investors/Partners**: Lead investor not publicly disclosed (Andreessen Horowitz was pitched but not confirmed as an investor). Partners include Bot Auto, WeRide, Pronto, Atoms (based on LinkedIn mentions). Also works with UMA (Utah Mining Association).
- **Growth Signals**: Headcount grew 3,575% YoY to 107 employees (as of mid-2026). 73 active job postings. Opened the world’s first autonomous mine (Copper One) in April/May 2026, generating significant industry news and social media engagement.

## Competitive Advantages
- **Software-first approach**: The company builds automation and data systems from the ground up, rather than layering tech onto legacy mining operations. This enables fully autonomous mining.
- **Vertical integration**: They develop, own, and operate mineral projects, controlling the entire value chain from extraction to processing.
- **Deep tech stack**: Use of AI/ML (TensorFlow, PyTorch), simulation, and real-time control systems to optimize mining operations.
- **First-mover in autonomous mining**: Copper One is claimed to be the world’s first autonomous mine, giving them a significant lead in operational efficiency and safety.

## Strategic Focus
- Scale autonomous mining operations beyond copper (lithium, graphite, uranium, etc.)
- Secure domestic supply of critical minerals for U.S. energy, AI, and defense needs.
- Continue aggressive hiring across engineering, operations, and field roles.
- Expand from Utah to additional sites (Houston engineering office, potential new projects).

## Why Work Here
- **Culture principles**: "Extreme Ownership", "Engineer Out Requirements, Then Automate", "Share Your Legos" – emphasizing accountability, simplification, and collaboration.
- **Work environment**: High-growth startup with a mission-driven focus on critical infrastructure. Offices in San Francisco (HQ), Houston (Engineering), and La Sal, Utah (mine site). Hybrid/remote policy not explicitly stated, but multiple office locations suggest flexibility for field vs. office roles.
- **Notable perks**: Opportunity to work on cutting-edge autonomous systems and AI in a traditional industry. Strong engineering culture with modern tech stack (React, Python, ML). Rapid career growth due to company expansion.
- **Talent sources**: Attracts talent from Tesla, Redwood Materials, Lilac, ExxonMobil, Amazon Web Services, and other tech/energy companies – indicating a high-caliber peer group.

## Sources
1. [marianaminerals.com](https://marianaminerals.com/)
2. [marianaminerals.com/careers](https://marianaminerals.com/careers)
3. [marianaminerals.com/about](https://marianaminerals.com/about)
4. [jobs.ashbyhq.com/marianaminerals](https://jobs.ashbyhq.com/marianaminerals)
5. [linkedin.com/company/mariana-minerals](https://www.linkedin.com/company/mariana-minerals)

## Other roles at Mariana Minerals

- [IP Counsel](https://feeny.ai/job/ip-counsel-mariana-minerals-san-francisco-p7p8qadb6xg7) — San Francisco, CA
- [Commercial Counsel](https://feeny.ai/job/commercial-counsel-mariana-minerals-san-francisco-c0kbyd0vszp7) — San Francisco, CA
- [Maintenance Training Opportunities](https://feeny.ai/job/maintenance-training-opportunities-mariana-minerals-moab-sd5f5z532gz1) — Moab, UT
- [Commissioning Engineer](https://feeny.ai/job/commissioning-engineer-mariana-minerals-houston-370gtt85kmfw) — Houston, TX
- [Production Planner](https://feeny.ai/job/production-planner-mariana-minerals-houston-xf1gadffk1h4) — Houston, TX
- [Sr./Staff Process Engineer - Detailed Engineering and Plant Design](https://feeny.ai/job/sr-staff-process-engineer-detailed-engineering-and-plant-design-mariana-sfmfv4wge0eb) — Houston, TX
- [Sr. Technical Recruiter](https://feeny.ai/job/sr-technical-recruiter-mariana-minerals-san-francisco-hr9b2676c4vw) — San Francisco, CA
- [Logistics Analyst](https://feeny.ai/job/logistics-analyst-mariana-minerals-san-francisco-y00p556jbf2y) — San Francisco, CA
- [Plant Design Manager](https://feeny.ai/job/plant-design-manager-mariana-minerals-houston-5hz4w45hkerz) — Houston, TX
- [Pilot Plant Operations Manager](https://feeny.ai/job/pilot-plant-operations-manager-mariana-minerals-houston-s78cx16gdpcm) — Houston, TX