Mesodyne is a startup company revolutionizing power generation with its innovative LightCell technology—using thermophotovoltaics to provide efficient, silent, reliable, long-endurance power from any fuel. By bridging the gap between batteries and internal combustion engines, Mesodyne's LightCell technology provides more than a 10x improvement in endurance for unmanned vehicles, wearables, and various other equipment. At Mesodyne, we are committed to bringing groundbreaking products to the industrial and defense sectors, with multiple existing contracts and numerous upcoming business opportunities.

We are seeking a highly skilled and motivated Principal Mechanical Engineer to own and lead our hardware prototyping efforts. This is a critical role for our next stage of growth, responsible for transforming concepts into functional, reliable hardware. Reporting directly to the CTO, you will manage a dedicated team to drive the complete prototyping lifecycle. You will be directly responsible for the project's success and paving the way for high-volume manufacturing.

Responsibilities

• Own the Prototyping Lifecycle: Take full ownership of prototype development projects, from initial concept and architecture through design, fabrication, and validation, ensuring the delivery of robust hardware.
• Lead and Mentor: Lead, mentor, and manage a dedicated, multi-disciplinary hardware team (initially one ME and one EE), fostering a culture of technical excellence, rapid iteration, and hands-on problem-solving.
• Set Technical Direction: Establish clear technical direction, define system requirements, and set priorities for the team, ensuring tight alignment with overall company objectives and customer needs.
• Hands-On Build and Assembly: As a hands-on leader, you will personally lead the assembly, integration, and testing of the first-generation systems. You and your team will be responsible for building the first ~10 units to deeply understand the design and refine the assembly process.
• Drive Design for Manufacturing (DFM): Champion the transition from prototype to product. Conduct rigorous design reviews with a focus on manufacturability, cost, and reliability. Develop the necessary documentation (CAD, drawings, assembly procedures) for a smooth handoff to manufacturing partners.
• Project Management and Reporting: Create and manage project schedules, budgets, and resource plans. Proactively identify and mitigate technical and programmatic risks. Clearly communicate status, progress, and challenges to the executive team and external partners.
• Technical Contribution: Act as a key technical contributor and subject matter expert, applying your deep knowledge to mechanical design (CAD), thermal/structural analysis, materials selection, and system-level troubleshooting.

Qualifications

• B.S., M.S., or Ph.D. in Mechanical Engineering or a closely related field.
• 8+ years of experience in hands-on hardware development, with a proven track record of taking complex mechanical or electromechanical products from concept to functional, tested prototypes.
• Proficiency in 3D CAD is essential.
• Demonstrated experience in project leadership and team management, with a history of successfully delivering complex hardware projects on time and on budget. Direct management experience is strongly preferred.
• Deep technical expertise in at least one of the following areas: thermal management, fluid systems, combustion, power generation, or precision mechanisms.
• Experience with the new product introduction (NPI) process, including designing for manufacturing (DFM/DFA) and transitioning products to internal or external manufacturing.
• Broad technical knowledge, including familiarity with electrical engineering principles sufficient to effectively lead EE team members in integrated system design and troubleshooting.
• Exceptional problem-solving skills, with the ability to architect solutions for complex, open-ended challenges.
• Strong communication (written and verbal) and collaboration skills, comfortable interacting with leadership, team members, customers, and vendors.

Location

This position is based at our facility in Somerville, MA.