Senior Process Engineer

About Magrathea

Based in Oakland, California, Magrathea is a global category leader in critical mineral production technology. Our mission is to rebuild the magnesium metal supply base, delivering secure access to one of the most critical materials on Earth. Magnesium is essential to the aluminum, steel, titanium, nuclear, defense, and aerospace industries but 95% of global supply comes from China where large amounts of coal are used to make metal.

This isn’t just an economic risk: it’s a national security threat, and Magrathea is fixing it. We’ve developed a next-generation electrolytic process to make magnesium metal from seawater and brines, unlocking a new path to industrial independence and to a cleaner environment for future generations. We’re backed by the earliest believers in Tesla and SpaceX, major European industrial families, and the U.S. Department of Defense.

If you’re ready to make a lasting real-world impact, let’s talk.

You’ll be joining a small, high-trust team of builders on a mission to stand up the first major electrolytic magnesium smelter this century. We’re doing it this decade. There are no pointless positions here, no layers of middle management, no meetings about meetings: just a deep focus on moving important work forward. You’ll be hands‑on from day one, shaping the core of a technology that will have major impacts on national security, clean technology, and industrial resilience.

If you’re the kind of person who is energized by hard, consequential problems, stays clear, calm, and effective when the work is ambiguous or urgent, and wants to build something that will matter far beyond the company, this role is for you.

Magrathea is seeking a highly capable, hands‑on Senior Process Engineer to support the development, operation, and scale‑up of our revolutionary electrolytic process technology. The role is ideal for someone who thrives in a fast‑paced R&D environment and combines strong mechanical, electrical, fabrication, and process troubleshooting skills with a practical, solutions‑oriented mindset. The successful candidate will play a critical role in designing, building, operating, and improving pilot‑scale systems, and transferring the knowledge gained to Magrathea’s demonstration plant in Southwest Arkansas.

This position requires creativity, initiative, sound technical judgment, strong operational problem‑solving skills, and clear communication across pilot plant, laboratory, and demonstration plant environments.

• Utilize piloting expertise to propose equipment/process innovations to execute development experiments at the demonstration plant.
• Operate, troubleshoot, and optimize demo‑scale electrolytic and high‑temperature processing equipment.
• Document pilot operational learnings for transfer to demonstration scale engineering and operations.
• Travel to Arkansas to support commissioning, startup, and operational activities at Magrathea’s demonstration plant.
• Diagnose and resolve mechanical, electrical, instrumentation, and process related issues.
• Fabricate and modify custom equipment using cutting, grinding, welding, drilling, and tapping tools.
• Design and modify piping, plumbing, electrical, and instrumentation systems.
• Support PLC controls, sensor integration, wiring, and data logging systems.
• Repair and perform preventative maintenance on pilot plant and laboratory equipment.
• Maintain accurate experimental records, operational logs, and communicate learnings and observations.
• Run pre‑established analytical methods to analyze samples from pilot or demonstration plant experiments.
• Collaborate with engineers, scientists, and technicians to improve processes and scale emerging technologies.
• Manage raw materials, process samples, and consumables while maintaining accuracy and traceability.
• Work safely in industrial and laboratory environments using appropriate PPE, including extended use of full‑face respirators and aluminized protective equipment for high temperature and molten material operations.

• Strong mechanical and electrical diagnostic and problem‑solving skills.
• Ability to understand the entirety of a…