Sr. Mechanical Engineer

Job Posting Start Date 01-20-2026 Job Posting End Date 03-27-2026

At JetCool, a Flex company, we're at the forefront of liquid cooling innovation, delivering advanced solutions that empower our partners in AI and high-performance computing. United by a shared purpose, our teams are pushing the limits of what's possible and tackling complex challenges.

A career at JetCool offers the opportunity to make a real impact by helping build smarter, more sustainable data centers. Together, we're not just advancing technology - we're redefining cooling standards to create a more sustainable tomorrow.

Job Summary

To support our extraordinary teams who build great products and contribute to our growth, we're looking to add a Senior Mechanical Engineer located in Littleton, MA.

Reporting to the Product Manager, the Senior Mechanical Engineer will play a key role in our product development team. This engineer will contribute to the design, analysis, and validation of advanced liquid cooling systems for processors, servers, and rack-level infrastructure.

What a typical day looks like:

• Contribute to design and development of liquid cooling components and assemblies, including cold plates, manifolds, tubing, mounting hardware, and heat exchangers.
• Perform mechanical and thermal analysis, including structural modeling, tolerance analysis, and CFD-assisted design input.
• Support prototype builds, functional testing, and iterative design refinement.
• Collaborate closely with electrical, thermal, and fluid systems engineers to optimize cooling performance at the processor, server, and rack levels.
• Apply Design for Manufacturing (DFM) and Design for Assembly (DFA) these are best practices to ensure scalable, high-quality production.
• Work with suppliers, manufacturing teams, and operations to transition designs from prototype to volume manufacturing.
• Create engineering documentation, including drawings, models, BOMs, and specification packages.
• Participate in design reviews and provide technical input to ensure robust, reliable solutions for demanding datacenter environments.
• Stay informed on emerging cooling technologies, industry standards, and datacenter trends.

The experience we're looking to add to our team:

• Bachelor's degree in mechanical engineering or related field (master's preferred).
• 6-10 years of mechanical engineering experience, ideally in thermal management, electronics cooling, or complex hardware systems.
• Hands-on experience designing components for liquid cooling systems, such as cold plates, heat exchangers, or fluid distribution systems.
• Familiarity with datacenter thermal challenges, particularly cooling processors, GPUs, and dense computer hardware.
• Proficiency in CAD tools (e.g., SolidWorks, Creo) and simulation tools (structural and thermal/CFD).
• Strong understanding of materials, machining, brazing, casting, plastics, and sealing technologies.
• Experience working through prototype, validation, and production release phases of hardware development.
• Excellent problem-solving skills and the ability to work on cross-functional engineering teams.
• Experience with rack-level and row-level cooling strategies (air and/or liquid).
• Knowledge of ASHRAE thermal guidelines or hyperscale datacenter requirements.
• Experience with reliability testing, environmental testing, and root-cause analysis.
• Exposure to modular datacenter environments or scalable cooling architectures.

BO18

What you'll receive for the great work you provide:

• 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

Pay Range (Applicable to Massachusetts)

$104,100.00 USD - $143,100.00 USD Annual

Job Category
Design, Process & Technology Engineering

Is Sponsorship Available?
No

JetCool is an Equal Opportunity Employer and employment selection decisions are based on merit, qualifications, and abilities. We do not discriminate based on: age, race, religion, color, sex, national origin, marital status, sexual orientation, gender identity, veteran status, disability, pregnancy status, or any other status protected by law. We're happy to provide reasonable accommodations to those with a disability for assistance in the application process. Please email and we'll discuss your specific situation and next steps (NOTE: this email does not accept or consider resumes or applications. This is only for disability assistance. To be considered for a position at JetCool, you must complete the application process first).