Principal Engineer Job Listing at Flex in Littleton, MA (Job ID WD207647)

Description

Job Posting Start Date 10-16-2025 Job Posting End Date 12-01-2025

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.

JETCOOL Technologies a Flex company is a fast-moving cooling solution provider, and successful MIT-spinoff, producing game-changing cooling solutions for aerospace, electric vehicles, and data centers. We are looking for a Principal Engineer based in Littleton, Ma.

What a typical day looks like:

• Work with JetCool commercial team to adapt customer requirements into an implementation ready design.
• Advance technology maturity of new secondary system design elements (water quality, flow regulation etc.).
• Work with manufacturing partners to establish modular design specifications for fast customer implementation and deployment.
• Lead communication and technical exchange with customers, build and cultivate customer and partner relationships, focusing on behind and beyond the rack cooling infrastructure
• Work with Flex supply chain to enable vendors and ensure specifications are up to date.
• Lead technical problem solving and pull in cross functional team to provide innovative thermal cooling system solutions

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

• Bachelor (or higher) of Science (B.S. in mechanical or aerospace engineering) and 5+ years of work experience and 2+ years thermal heat rejection architecture / infrastructure experience  
• Excellent first principles knowledge in mechanical engineering, fluid dynamics, thermodynamics, and system heat transfer
• Track record of delivering thermal heat rejection solutions to customers with high quality and on schedule
• Strong communication skills
• Strong problem-solving and thermal / fluid system analysis skills
• Ability to specify smart heat rejection system architectures

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

Is Sponsorship Available?

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).