Thermofluid Systems Test Engineer

Flextronics - The Flex Company; Littleton (MA); On-site; USD 126,500 - 173,900; Full time

Benefits offered by this job

Full range of medical, dental, and vision plans

Life Insurance

Matching 401(k) Contributions

Tuition Reimbursement

Vacation and Paid Sick Time

Job summary

Flextronics - The Flex Company is seeking a Thermofluid Systems Test Engineer in Littleton, MA. This role requires 7+ years of hands-on experience with thermo-fluid systems and involves testing, designing, and executing test plans for advanced cooling solutions.

You will manage the testing of Coolant Distribution Units (CDUs) to deliver actionable insights for product design, contributing to innovation in high-performance computing and data centers.

The position offers a comprehensive benefits package including medical, dental, and retirement plans.

Qualifications

• 7+ years of hands-on experience testing thermo-fluid systems.
• Strong practical understanding of fluid dynamics and thermodynamics.
• Demonstrated experience with performance and qualification testing.

Responsibilities

• Own hands-on testing of Coolant Distribution Units (CDUs).
• Design and operate automated thermo-fluid test stands.
• Execute test plans and deliver insights to engineering teams.

Skills

Testing and qualifying thermo-fluid systems

Fluid dynamics

Data acquisition and analysis

Troubleshooting complex system-level issues

High proficiency with PLC-based controls

Job description

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 Thermofluid Systems Test Engineer located in Littleton, MA. Reporting to the Mechanical Development Associate Principal Engineer, the Thermofluid Systems Test Engineer will have strong hands‑on expertise in thermofluid systems and will take ownership from early development through qualification and product release.

Responsibilities

• Own hands‑on testing of Coolant Distribution Units (CDUs) and related subsystems, including pumps, heat exchangers, tubing, valves, and fluids.
• Design, build, instrument, and operate automated thermo‑fluid test stands to characterize flow, pressure drop, thermal performance, and system behavior.
• Develop and maintain PLC‑based controls, data acquisition, and automation for repeatable, long‑duration, and qualification testing.
• Execute test plans, analyze results, and deliver clear, test‑driven feedback to design and systems engineering teams.
• Support design reviews and product decisions by translating test data into actionable insights and risk assessments.
• Improve lab capability by identifying gaps in tooling, instrumentation, controls, and test coverage for CDU development and validation.
• Support troubleshooting and root‑cause investigations across development, qualification, production, and field issues related to thermo‑fluid performance.

Qualifications

• 7+ years of hands‑on experience testing and qualifying thermo‑fluid systems in data center cooling, automotive, medical, or industrial environments, including direct experience with CDUs or comparable systems.
• Strong practical understanding of fluid dynamics, thermodynamics, and heat transfer, applied to test execution and data interpretation.
• Demonstrated experience leading performance and qualification testing, including flow, pressure, thermal efficiency, durability, and fault‑mode testing.
• Proven ability to design, build, instrument, and commission custom thermo‑fluid test stands with pumps, valves, heat exchangers, sensors, and safety interlocks.
• Experience developing and executing structured test plans, qualification matrices, and acceptance criteria, with ownership of test execution and results.
• Strong data acquisition and analysis skills, including sensor selection, calibration, data logging, and post‑processing.
• Proficiency with PLC‑based controls and test automation, including modifying control logic for automated sequences and safe system operation.
• Demonstrated ability to troubleshoot complex system‑level issues through hands‑on testing and structured root‑cause analysis.
• Ability to clearly document and communicate test plans, results, failures, and margin assessments to engineering teams and senior stakeholders.

What you’ll receive

• 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 per year.

Job Category: Design, Process & Technology Engineering

Is Sponsorship Available? No

Equal Opportunity Employer

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 [e-mail] 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).