---
title: 'Senior/Staff Chemical Process Engineer at Mariana Minerals'
canonical: 'https://feeny.ai/job/senior-staff-chemical-process-engineer-mariana-minerals-san-francisco-34b0xfs3fzep'
type: 'job'
last_seen: '2026-10-30'
---

# Senior/Staff Chemical Process Engineer at Mariana Minerals

- **Company:** Mariana Minerals
- **Location:** San Francisco, CA
- **Compensation:** $140k–$175k
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-10-26
- **Last confirmed live:** 2026-10-30
- **Apply:** https://jobs.ashbyhq.com/marianaminerals/29a1a6e4-db3f-406d-af65-e7c00c3d8ff6

## 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.

## Role Overview

Mariana Minerals is looking for a highly motivated Sr./Staff Process Engineer to work on building the critical minerals supply chain to support the world’s energy transition and to supply metals necessary for technology and AI, energy, mobility, and defense. As a Sr./Staff Process Engineer at Mariana Minerals, you will lead the development and deployment of state-of-the-art chemical refining processes, while also supporting development of software for capital project execution and automated plant optimization. Responsibilities will include leading process area and equipment scopes from concept through to design, installation, commissioning, ramp, and handover to the operations team.

## What You’ll Bring

- Lead process area and equipment scopes from concept and modeling validation, through procurement, engineering, fabrication, installation, commissioning, and ramp
- Manage external equipment providers, technology licensors, and engineering companies to deliver fully integrated and functional mineral refining scopes.
- Build heat and material balances for integrated mineral refineries
- Develop Process Flow Diagrams (PFDs) and Piping & Instrumentation Diagrams (P&IDs) for mineral refineries
- Build first-principles-based models of chemical reactors and unit operations to validate and scale-up designs
- Identify, evaluate, and implement engineering solutions to optimize process designs, confirming functionality and performance under various operating conditions
- Work closely with cross-functional teams including lab technicians, pilot plant engineers, process engineers, project execution teams, and more to scale designs from lab through to commercial scale
- Work closely with the software and machine learning teams to automate capital project execution workflows and develop equipment and plant optimization algorithms

## What You’ll Bring

- Strong understanding of engineering fundamentals and demonstrated ability to leverage this understanding to solve challenging problems
- Strong foundation in chemical engineering, metallurgical engineering, or process engineering, with demonstrated ability to apply engineering fundamentals to complex systems
- Experience with plant & equipment engineering and design. Including but not limited to:
- Brownfield modifications and upgrades
- Greenfield design
- Evaluation and optimization of operating facilities
- Experience with the following industries and/or production environments:
- Industrial manufacturing
- Large-scale mining or mineral processing, particularly across hydrometallurgy, electrometallurgy, and pyrometallurgy
- Large-scale chemical production processes
- Engineering, procurement, and construction (EPC/EPCM) firms

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)

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