Test Engineering Intern - Summer 2026

As a Test Engineering Intern on Lunar's Automatic Test Equipment (ATE) team, you'll work hands-on alongside mechanical, electrical, firmware, and manufacturing engineers to design, build, integrate, and deploy the test fixtures that validate our next-generation home energy products. Along the way, you'll build real working knowledge well beyond mechanical, picking up how circuits, firmware, and full hardware systems come together in shipping a product. This is a great role for a rising senior or recent graduate who is passionate about clean energy technology, thrives on cross-functional collaboration, and does their best work in a fast-paced, dynamic environment. 

Lunar Energy was founded to transition homes to 100% clean energy—making our electricity greener, our air cleaner and our energy more safe, secure and reliable for all. We’re a fast-growing, global company building the world’s best clean energy products to electrify all homes and connect communities to form clean, resilient virtual power plants.

On a given day at Lunar, you'll likely…

• Design mechanical test fixtures in 3D CAD: the equipment that validates the hardware going into real customers' homes. 
• Specify and validate components to meet the test specifications provided by Electrical, Firmware, and Manufacturing Engineer teams.
• Prototype fast with our in-house 3D printers, laser cutters, and machine shop. Sketch it in the morning, print it by lunch, try it on a bench by the end of the day. 
• Bring fixtures to life on the floor: Verify test-points, debug mechanical issues, and work side-by-side with technicians.
• Collaborate with external fabrication vendors to take your designs from CAD to production-ready drawings, quotes, and first-article inspections all sit with you. 
• Write documentation clear enough that the team can replicate your work and keep it running for years.

Desired Skills:

• Rising senior in a B.S. program, recent graduate (within the last year), or student in the final year of an M.S. program in Mechanical Engineering, Mechatronics Engineering, or a closely related field.
• Proficiency with at least one 3D CAD package (e.g., SolidWorks, Fusion 360, Onshape, or equivalent).
• Hands-on prototyping experience: 3D printing (FDM/SLA), laser cutting, basic machining, or general fabrication in a maker space, lab, or formula-style student project.
• Working understanding of tolerance stack-ups, GD&T basics, and fasteners/joining methods.
• Comfort reading mechanical drawings, electrical schematics, and bills of materials.
• Basic electrical/electronics fluency: comfortable with a multimeter, DMM, oscilloscope, bench power supply, and simple wiring.
• Familiarity with pneumatic actuation, cam mechanisms, or other mechanical actuation for fixtures.
• Some scripting ability for simple automation, data processing, or tool integration.
• Awareness of DFX (Design for Manufacturing, Assembly, Test) principles. 
• Thoughtful use of AI assistants and coding tools (e.g., Claude, Gemini, ChatGPT) in your engineering workflow—including good judgment about when outputs need verification and awareness of confidentiality practices.

Our DE&I Philosophy: Lunar Energy is an equal opportunity employer. We are committed to attracting, developing and retaining diverse talent by supporting an inclusive workplace. Lunar recruits, hires, trains, promotes, compensates, and administers all personnel actions without regard to race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, disability status or any other status protected by applicable law.

Our Compensation Philosophy: Our goal is to ensure that all Lunar Energy employees are fairly compensated. Please note that the hourly range information that follows is a good faith estimate for this position provided pursuant to the Pay Transparency for Pay Equity Act for California applicants. The hourly range estimate for this position depending on level of experience is $25-$40 USD

The actual offer, reflecting the total compensation package & benefits, will be at the company’s sole discretion, and determined by factors including but not limited to years of experience, job level, geographic location, and other relevant business considerations. The company also reserves the right to amend or modify this job description, employee perks, and benefits at any time.