Mechanical Engineer Intern

THE ROLE

We are seeking a Mechanical Engineering Intern to join Heirloom’s Mechanical Team for the upcoming Fall/Water for a 10-12 week internship. In this role, you will support the design, build, and deployment of next-generation carbon removal systems. This is an opportunity for someone who wants hands-on ownership, exposure to industrial-scale hardware, and experience working in a fast-paced climate tech startup.

WHAT YOU’LL DO

Depending on your strengths and team priorities, you may: Support mechanical design of subsystems and components (structures, mechanisms, machine design) Develop CAD models and 2D drawings for fabrication Assist with prototyping, assembly, and field testing of hardware Conduct engineering analyses (tolerance stacks, FEA, etc.) Support root cause investigations and design improvements on equipment Help document designs, test results, and lessons learned Collaborate cross-functionally with process, electrical, controls, and operations teams You’ll leave the internship having directly contributed to hardware that captures CO₂ from the atmosphere.

WHAT YOU’LL BRING

Pursuing a BS or MS in Mechanical Engineering (or related field) or have recently graduated Hands-on experience building things (lab work, shop experience, project teams, internships, personal projects) Strong understanding of engineering fundamentals (statics, dynamics, kinematics, thermodynamics, fluid mechanics) 3D CAD experience Engineering testing methodology; ability to design experiments and collect data Self-starter, critical thinker, and problem-solving skills Team player with excellent verbal & written communication and interpersonal skills

NICE TO HAVE

Familiarity with formal engineering documentation (ANSI mechanical drawings, electrical schematics, Process & Instrumentation Diagrams) Hands-on fabrication experience: e.g. woodworking, machining, welding, etc. Mechatronics systems experience (e.g. Arduino, Raspberry Pi or similar with motion components) Familiarity with kinematic systems (e.g. gears, belts, leadscrews, linkages, etc.) Experience on robotics, solar car, formula SAE, or similar engineering teams

COMPENSATION & LOGISTICS

Internship Duration: 10-12 weeks (6 month co-ops also will be considered) Start date: Anytime between September 2026 and January 2027 Compensation: Comp will be: $5,000 relocation/housing allowance paid upfront plus hourly pay. Juniors: $30/hour Seniors/grads: $34/hour You don’t have to have every listed requirement and skill to be a great fit. If you are passionate about this opportunity and think you have the skills to succeed, please apply! Our Commitment to Diversity, Equity, and Inclusion We encourage you to apply if you identify as Black, Native Hawaiian or Pacific Islander, American Indian or Alaskan Native, Hispanic or Latino, LGBTQ+ – or with any other underrepresented group – even if you don’t tick all the boxes in the description below. Perks and Benefits for Eligible Employees Excellent health, dental and vision insurance covered up to 100% by Heirloom. FSA option. 16 weeks paid parental leave for all Heirloom employees. Generous stock options. Unlimited PTO for exempt (salaried) employees & 120 hours for full time non-exempt (hourly) employees. 401(k). Monthly health and wellness reimbursement. Annual education and conference budget. Our Principles Radical Honesty. We strive to foster an inclusive environment premised on transparency and respect. We push for excellence, yet always remain thoughtful when challenging each other. Persistent Optimism. We show up to work with optimism and don’t shy away from a challenge. We recognize that the ambitious nature of our mission requires hopefulness, dedication, and persistence. Maximize Learning. Compounding knowledge is our key to victory - we continuously hone our crafts, seek the fastest paths to improve, and are quick to absorb and apply new insights. Why you should join Heirloom We are solving the challenge 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 are a world-class team. We are 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 remain united, resilient, and optimistic. We recognize the magnitude of the challenge ahead of us, yet believe that we can contribute to mitigating the worst effects of climate change. It won’t be easy, but we won’t quit. We are backed by credible climate partners. 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.