Senior Mechanical Engineer, High Volume Design

Senior Mechanical Design Engineer

As a Senior Mechanical Design Engineer on the high-volume design team, you will own the design and execution of complex mechanical subsystems that directly influence the economics, reliability, and scalability of our core technology. This role spans early-stage R&D through NPI and site-scale deployment, requiring strong engineering fundamentals, sound judgment, and a bias toward practical, manufacturable solutions.

You will be expected to challenge assumptions, rigorously evaluate tradeoffs, and push the boundaries of design and manufacturing while maintaining a clear focus on cost, reliability, and long-term operability. This is a high-ownership individual contributor role with significant technical leadership and cross-functional influence.

What You'll Do

• Own end-to-end design of complex mechanical subsystems, from requirements definition and architecture through validation, production ramp, and deployment
• Drive subsystem performance across cost, reliability, manufacturability, and serviceability, with direct impact on $/ton CO? economics
• Design low and high-volume components using a variety of manufacturing processes, including sheet metal stamping, casting, roll forming, and extrusions
• Lead design trade studies using first-principles analysis, data-driven methods, and sound engineering judgment
• Design and develop product-level test equipment, fixtures, and validation strategies to support Design for Reliability (DfR), including accelerated life testing, stress testing, and failure-modedriven validation to ensure robust subsystem and system performance over the intended service life
• Partner closely with suppliers, equipment operators, manufacturing, and supply chain teams to ensure designs are robust, scalable, and production-ready
• Generate and review detailed 2D drawings with proper GD&T, aligned with production and inspection standards
• Support rapid prototyping and iterative development cycles while maintaining a clear path to NPI rigor
• Act as a technical leader within the team by mentoring peers, driving best practices, and raising the bar for engineering quality

What You'll Bring

• 5+ years of experience designing and delivering products through the full lifecycle, from concept to production
• Strong passion for product design and solving complex engineering problems with simple, robust solutions
• Excellent engineering fundamentals, with the ability to apply first principles, modeling, and data to real-world design decisions
• Experience applying Design for Reliability (DfR) principles, including failure mode identification, reliability modeling, accelerated life and stress testing, and translating test results into durable design improvements
• Experience with engineering analyses such as reliability modeling, tolerance analysis, FEA, fatigue analysis, and root cause analysis
• Demonstrated ability to lead technically complex projects or subsystems with minimal supervision
• Proven track record of working cross-functionally to balance competing requirements and constraints
• Experience producing clear, accurate drawings and specifications suitable for manufacturing and inspection
• Strong sense of ownership, accountability, and follow-throughdelivering high-quality work on schedule

Bonus Points

• Hands-on experience designing sheet metal (stamping, press brake), weldments, and plastic parts (e.g., injection molding, thermoforming)
• Background in random vibration and fatigue testing, metallurgy, material and test standards
• Experience managing development in a product lifecycle management system (PLM)
• Comfort operating in both fast-paced R&D environments and the structured rigor of NPI execution
• Experience using NX in a production or industrial context

Why You Should Join Heirloom

• We are solving the engineering problem of our generation. Climate change is an existential threat, and we need as many of the world's motivated minds as possible to help. There is no greater challenge or opportunity than fighting climate change.
• We have done this before. We're engineers, scientists, and concerned humans from a variety of backgrounds and experiences who are pooling our knowledge and skills to collectively build a more equitable, prosperous future for all.
• We are a united, resilient, and optimistic bunch. We are all here for the same reason - to slow climate change. We recognize the magnitude of the challenge ahead of us, and believe we can solve it. We can see a hopeful future where we eventually reverse climate change. It won't be easy, but we won't quit.
• We are backed by the best climate partners in the world. We're well funded by investors from Breakthrough Energy Ventures, Ahren Innovation Capital, Carbon Direct, Microsoft, Lowercarbon Capital, ARPA-e and the National Science Foundation. Our early customers include Stripe, Shopify, and Klarna, and we're building durable partnerships that enable us to tackle this decades-long problem.

Perks and Benefits

• Robust health coverage. Excellent health, dental and vision insurance covered up to 100% by Heirloom. FSA option.
• Generous parental leave. 16 weeks paid leave for all Heirloom employees, regardless of primary/secondary caregiver status.
• Generous stock options.
• Flexible time off. Unlimited PTO for exempt (salaried) employees & 120 hours for full time non-exempt (hourly) employees.
• 401(k).
• Stay healthy. Monthly health and wellness reimbursement.
• Learn on the job. Robust annual education and conference budget, including airfare and hotel costs.