Senior Mechanical Engineer - Liquid Cooling

Job Posting Start Date 09-12-2025 Job Posting End Date

Flex is the diversified manufacturing partner of choice that helps market-leading brands design, build and deliver innovative products that improve the world.

A career at Flex offers the opportunity to make a difference and invest in your growth in a respectful, inclusive, and collaborative environment. If you are excited about a role but don't meet every bullet point, we encourage you to apply and join us to create the extraordinary.

Job Summary

JETCOOL Technologies, a Flex company, is seeking a dedicated, dependable Senior Mechanical Engineer in Littleton, MA to contribute to technical programs across our core data center business. The position will be responsible for executing engineering programs involving thermal analysis, mechanical design, detailed drawings, fabrication with new and existing suppliers, and environmental/thermofluidic testing. Successful candidates will be comfortable participating in the technical execution of multiple programs simultaneously but also, when needed, taking on tasks as an individual contributor to meet project deadlines. Successful candidates will be skilled in mechanical design (leading design reviews, approving engineering drawings, etc.) and be highly effective communicators to the team. The engineer should be able to think on their feet and clearly communicate technical ideas and concepts to various audiences. Join us in shaping the future of data centers while making a significant impact on sustainability. Apply now to be part of our dedicated team of engineers and thinkers.

JetCool has a mission to continuously innovate next-generation cooling solutions to enable the devices that fuel a more sustainable tomorrow. JetCool designs and delivers microconvective cooling® technology for high-power electronics, enabling our customers to achieve unprecedented performance and unrivaled sustainability improvements. Our technology creates a ripple effect, enabling the businesses we serve to become more sustainable, profitable, and efficient. Join us to be part of some of today's fastest growing industries, while having a positive impact on society through technology.

• Lead the mechanical architecture of components given fundamental specified spatial constraints and targets.
• Collaborate with JetCool internal and broader Flex design teams to push designs to completion.
• Conduct mechanical simulations to ensure product robustness and limit the liability of fluid connections via careful mechanical design, considering all external and internal loading.
• Advance custom part designs from easy-to-prototype configurations to parts that offer improved cost profiles while maintain the required mechanical reliability.
• Develop and review engineering specifications, and documentation for the mechanical components and systems.
• Assist in maintaining a strong best practice culture and driving additional foundational knowledge and IP.
• Provide technical guidance and mentorship to junior engineers, fostering a culture of continuous learning and development.
• Participate in design reviews, presenting technical findings and recommendations to internal and external stakeholders.

• Bachelor of Science degree in Mechanical Engineering or closely related field.
• Minimum of 6 - 8 years of post-collegiate experience, with 3+ years in designing and engineering fluid systems, preferably within the data center cooling, automotive, aerospace, medical, or nuclear industries.
• Significant experience in design for high volume manufacturing processes including welding, brazing, die casting, and polymer molding.
• Strong analytical and problem-solving skills, with the ability to effectively troubleshoot and optimize mechanical robustness.
• Excellent communication skills to motivate technical direction and concepts to design team members and management.

• Full range of medical, dental, and vision plans
• Life Insurance
• Short-term and Long-term Disability
• Matching 401(k) Contributions
• Vacation and Paid Sick Time
• Tuition Reimbursement