Product Engineer (Mechanical)

Department: Engineering

Location: San Francisco

Employment Type: FullTime

About Unlimited:

Unlimited is an AI-native engineering and construction company reimagining how large-scale physical infrastructure gets built – from factories to power plants to entire industrial systems. We’re already delivering real projects with customers across multiple industries, using our AI-first engineering platform to design an order of magnitude faster than industry norms.

Backed by a $12M seed round from Andreessen Horowitz, CIV, Bessemer, and other leading investors, we’re building a small, engineering-led team to scale what’s already working and to take on one of the most important challenges of the coming decades.

About the Role:
We’re looking for mechanical engineers who take ownership from initial design through construction and want to help build the product that will automate those workflows. You’ll design the systems that move the physical world, from industrial fluid networks and rotating equipment to HVAC, process utilities, and mechanical structures across mining, critical minerals, power plants, data centers, and advanced manufacturing.

This isn’t a traditional role. You’ll work inside our AI-native engineering framework, where the tools learn from how you size equipment, route systems, solve constraints, and make tradeoffs. Your judgment becomes reusable logic that improves with every project. The platform you help build will shape how Unlimited designs, models, and deploys mechanical systems at industrial scale. The right person sees this not as project-by-project mechanical design but as a chance to define the system that transforms how mechanical engineering gets done across the built world.

What You’ll Do:

• Lead design, integration, and commissioning of mechanical and utility systems across entire facilities including piping, heat exchangers, pumps, compressors, HVAC, and process utilities.

• Use and improve Unlimited’s AI-powered engineering tools to automate design, simulation, and coordination.

• Collaborate with software, electrical, and civil engineers to deliver complete, field-ready systems.

• Participate in projects from concept through commissioning, validating automated designs against real-world constraints and refining system logic.

• Develop operational procedures and field test plans for mechanical systems.

• Identify failure modes, run root-cause analyses, and drive rapid design iteration for improved reliability and performance.

You Have:

• A strong foundation in mechanical or process engineering, with experience designing, integrating, and commissioning systems for factories or other large industrial facilities.

• Hands-on exposure to at least one of: cryogenic or high-pressure fluid systems, industrial HVAC, large rotating equipment, or structural/mechanical integration.

• Familiarity with mechanical modeling tools (CAD, FEA, or process simulation) and an interest in how they can be automated or reimagined.

• Curiosity about AI and a desire to apply it to real-world engineering problems

• Ability to move fast, learn new tools, and iterate directly with customers and project teams.

• Excellent communication skills with the ability to collaborate across disciplines, translating between engineering domains to solve complex, cross-functional problems.

• Comfort working under tight deadlines and ambiguity in a fast-paced, high-output environment.

• Ability to travel to projects and customers as needed.