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Principal Mechanical Engineer

Flex
Flex Salary
Littleton, MA Full Time
POSTED ON 9/30/2025
AVAILABLE BEFORE 10/30/2025
Flex is the diversified manufacturing partner of choice that helps market-leading brands design, build and deliver innovative products that improve the world. We believe in the power of diversity and inclusion and cultivate a workplace culture of belonging that views uniqueness as a competitive edge and builds a community that enables our people to push the limits of innovation to make great products that create value and improve people's lives. 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.

We are seeking a Principal Mechanical Development Engineer to add to our team in Littleton, MA. The Principal Mechanical Design Engineer will be responsible for leading the mechanical design activity implementing innovative and cost-effective product solutions in order to support the organization from prototype development through full-scale production.

JetCool, a Flex company, 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.

What a typical day looks like:

  • Define new mechanical product architecture, analyze performances and provide feasibility studies
  • Lead and execute the mechanical system, subsystem and part design of products from requirement specification up to transfer to manufacturing including fabrication, testing, verification and validation of engineering prototypes
  • Support the creation of product design documentation requirements
  • Work with mechanical engineers in design and development of miniaturized system
  • Be a technical lead closing the gap between Marketing team and Mechanical Design teams
  • Work within the project team adopting time and cost-effective solutions
  • Provide high quality technical reports supported by simulations and/or lab tests
  • Investigate new technologies and trends, assisting in generating production and technology roadmaps that support customer expectations with close relationship with vendors
  • Support actively customer base with design improvements that enhance manufacturability and assembly while minimizing costs
  • Promoter and coordinator of design reviews and DFx reviews

The experience we are looking to add to our team:

  • Bachelor’s degree in Mechanical/Aerospace/Biomedical engineering
  • 8 years of experience in engineering with proven technical leadership
  • Previous experience in designing medical devices, handset devices or white goods is a plus
  • Use of CAD tool suite

-Site

Flex is an Equal Opportunity Employer and employment selection decisions are based on merit, qualifications, and abilities. We celebrate diversity and 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 Flex, you must complete the application process first).

Salary : $123,500 - $169,800

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