Senior Mechanical / Thermal Engineer - thermal system design and development

InnoTech Staffing • Cambridge, MA

19h • Onsite

About The Position

InnoTECH Staffing is seeking an experienced Senior Thermal Engineer to work at the intersection of materials science, applied physics, and thermal engineering for an exciting start-up in Cambridge, MA. This requires being onsite 5 days a week. There is no sponsorship available. Overview This role will be primarily responsible for expanding experimental and design capabilities, improving the performance and efficiency of prototype systems, and ensuring that the testing programs generate clear, actionable insights. We are seeking a talented and creative problem solver who can tackle complex, open-ended challenges in thermal systems and thermofluidics with a disciplined engineering approach. The ideal candidate will thrive in a small, fast-moving startup environment and be willing to take on a range of responsibilities as needed to advance the technology. While the primary focus will be designing and executing investigative experiments and validation testing in the laboratory, members of our team are expected to contribute broadly across the organization. This includes prototype and product design, materials development, systems engineering, controls, and occasional support for company-building initiatives. The successful candidate will bring at least five years of experience in thermal, mechanical, chemical, or related engineering disciplines, with demonstrated expertise in the design, modeling, and validation of thermal systems in energy, HVAC, refrigeration, or similar applications. Strong hands-on experience working with prototype hardware is essential. Familiarity with heat exchangers, phase-change phenomena, and coupled thermal–fluid systems is strongly preferred.

Requirements

• 5+ years of industry experience designing and developing thermal systems in energy, HVAC, refrigeration, or related industries
• Strong hands-on experience designing, building, and testing prototype hardware or engineering systems
• Experience applying thermal modeling tools and analytical methods to guide design decisions and reduce development risk
• Deep understanding of heat transfer, thermodynamics, and fluid mechanics
• A disciplined engineering mindset that balances creative problem solving with rigorous experimental design, including familiarity with structured testing, statistical methods, and systematic knowledge development
• A pragmatic approach focused on generating results that directly enable the next stage of technology development
• The ability to work independently, collaborate effectively within a small team, and take leadership when needed

Nice To Haves

• Familiarity with heat exchangers, phase-change phenomena, and coupled thermal–fluid systems is strongly preferred.

Responsibilities

• Design and analyze key components of solid refrigerant systems, including heat exchangers, thermal interfaces, and system-level heat flow paths
• Develop analytical and numerical models to predict system behavior, identify performance bottlenecks, and guide engineering decisions
• Use company test rigs and prototype subsystems to characterize thermal and mass transport properties of solid refrigerant composites
• Plan, execute, and interpret thermal performance experiments on prototype subsystems and integrated systems
• Collaborate with engineering team members to design experimental equipment and develop reliable testing methodologies
• Improve and expand test infrastructure, instrumentation, and data acquisition systems
• Contribute to the development of company culture, technical rigor, and engineering best practices
• Mentor interns and co-op students working on research and development projects

Benefits

• We cover 60% of the medical insurance premiums for our employees and their dependents on our base plans, and 100% of dental, and vision insurance premiums.
• We offer an unlimited Paid Time Off policy and encourage people to take regular vacation.
• We provide an employee-contribution 401(k) plan in addition to many other benefits.
• Every employee, regardless of gender identity or expression, is also eligible for 12 weeks of paid parental bonding leave after their 1-year anniversary at the company.

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: No Education Listed