Sr. Mechanical Development Engineer

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


Application Deadline:
Applications for this job position will be accepted for at least five days following the job posting start date below and continuing until the end date below or until the position is filled. This posting may close sooner due to application volume.
Job Posting Start Date 10-14-2026 Job Posting End Date 10-16-2026


The base pay range for this position is provided below. The final base rate offered will be determined using job-related, non-discriminatory criteria, including but not limited to experience, qualifications, geographic location, education, external market data, and internal equity.
$126,500.00 USD - $173,900.00 USD Annual
Job CategoryDesign, 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 accessibility@flex.com 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).