Flex logo

Sr. Mechanical Design Engineer

FlexLittleton, MA

$126,500 - $173,900 / year

Automate your job search with Sonara.

Submit 10x as many applications with less effort than one manual application.1

Reclaim your time by letting our AI handle the grunt work of job searching.

We continuously scan millions of openings to find your top matches.

pay-wall

Overview

Schedule
Full-time
Career level
Senior-level
Remote
On-site
Compensation
$126,500-$173,900/year
Benefits
Health Insurance
Dental Insurance
Vision Insurance

Job Description

Job Posting Start Date 05-06-2026 Job Posting End Date

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 Sr. Mechanical Design Engineer located in Littleton, MA.

Reporting to the Mechanical Development Associate Principal Engineer the Sr. Mechanical Design Engineer will take full ownership of converting concepts and SolidWorks CAD models into robust, manufacturable, and production‑ready designs. This role is responsible not just for creating models, but for expertly detailing SolidWorks designs into clear, complete, and executable documentation that enables low‑cost, high‑quality, repeatable manufacturing.

What a typical day looks like:

  • Take end‑to‑end ownership of detailed mechanical design, from early concepts through fully released, production‑ready SolidWorks models and documentation.
  • Expertly detail SolidWorks parts and assemblies, converting conceptual designs into fully defined geometry with proper tolerances, fits, interfaces, and manufacturing intent.
  • Own tolerance stack‑ups, GD&T application, and fit/function strategy, ensuring designs assemble reliably and perform as intended in production.
  • Produce high‑quality engineering drawings (machined parts, sheet metal, weldments, and assemblies) using ASME Y14 and applicable industry standards, with clarity suitable for external suppliers.
  • Own weldment modeling and drawings in SolidWorks, including joint design, weld symbols, fabrication notes, and distortion considerations.
  • Select and specify materials, seals, gaskets, fasteners, and finishes, balancing performance, manufacturability, durability, cost, and supply‑chain constraints.
  • Build and maintain complete documentation packages, including SolidWorks models, drawings, specifications, and structured BOMs, with accountability for accuracy and completeness.
  • Define and own BOM structure and product hierarchy, supporting manufacturing, sourcing, configuration control, and lifecycle management.
  • Lead design reviews with an ownership mindset, proactively identifying tolerance risk, manufacturability issues, assembly challenges, and cost drivers.
  • Partner closely with manufacturing, quality, and suppliers to resolve build issues, clarify documentation, and continuously improve design robustness and producibility.

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

  • 8+ years of experience in detailed mechanical design with direct ownership of production‑released hardware.
  • Expert proficiency in SolidWorks, including advanced part modeling, assemblies, configurations, and drawing creation with manufacturing‑ready detail.
  • Demonstrated mastery of GD&T, tolerance analysis, and precision detailing, applied intentionally to real manufacturing and assembly constraints.
  • Extensive experience creating clear, unambiguous engineering drawings for machined parts, sheet metal, weldments, and complex assemblies.
  • Strong working knowledge of ASME drawing standards and common manufacturing best practices.
  • Proven experience detailing fabricated and welded structures, including weld definitions, callouts, and fabrication clarity.
  • Deep understanding of manufacturing processes (machining, sheet metal, welding, precision assembly) and how SolidWorks design decisions affect cost, quality, and yield.
  • Experience selecting and applying materials, seals, gaskets, and hardware in demanding mechanical systems.
  • Strong experience developing and maintaining structured BOMs, part numbering schemes, and controlled documentation sets.
  • Demonstrated ownership mentality-taking responsibility for design quality, manufacturability, cost, and downstream success through production.
  • Clear communicator who can effectively work with engineers, manufacturing teams, and suppliers to drive issues to closure.

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)

$126,500.00 USD - $173,900.00 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 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).

Automate your job search with Sonara.

Submit 10x as many applications with less effort than one manual application.

pay-wall

FAQs About Sr. Mechanical Design Engineer Jobs at Flex

What is the work location for this position at Flex?
This job at Flex is located in Littleton, MA, according to the details provided by the employer. Some roles may also include multiple work locations depending on the requirement.
What pay range can candidates expect for this role at Flex?
Candidates can expect a pay range of $126,500 and $173,900 per year.
What employment applies to this position at Flex?
Flex lists this role as a Full-time position.
What experience level is required for this role at Flex?
Flex is looking for a candidate with "Senior-level" experience level.
What benefits are offered by Flex for this role?
Flex offers following benefits: Health Insurance, Dental Insurance, Vision Insurance, Disability Insurance, Life Insurance, Paid Vacation, Paid Sick Leave, 401k Matching/Retirement Savings, and Tuition/Education Assistance for this position. Actual benefits may vary depending on the employer's policies and employment terms.
What is the process to apply for this position at Flex?
You can apply for this role at Flex either through Sonara's automated application system, which helps you submit applications 10X faster with minimal effort, or by applying manually using the direct link on the job page.