Senior Thermal & Fluid Systems Engineer

Flextronics - The Flex Company; Littleton, Northern (MA, KY); Hybrid; USD 154,000 - 211,000; Full time

Benefits offered by this job

Medical, dental & vision

Life Insurance

Disability insurance

401(k) matching

Vacation & paid time off

Tuition reimbursement

Job summary

JetCool, a Flex company, is seeking a Principal Thermal Mechanical Engineer in Littleton, MA to lead fluid and thermal system architecture from concept to production. You will mentor engineers, drive simulation and testing, and collaborate with customers to validate performance and compliance across data center cooling applications.

Your leadership will span design reviews, development activities, and cross‑functional execution to deliver reliable, scalable cooling solutions while advancing

Qualifications

• Minimum 7+ years designing and engineering fluid systems in data center thermal management or related industries.
• 3+ years direct experience with Coolant Distribution Units (CDUs).
• Deep expertise in fluid dynamics, thermodynamics, and heat transfer.

Responsibilities

• Lead the architecture, design, analysis, and optimization of complex fluid and thermal systems—including pumps, fluids, tubing, heat exchangers, and associated components for advanced computing and processing platforms.
• Own mechanical and fluid system deliverables from concept through production, ensuring designs meet performance, reliability, manufacturability, and compliance requirements.
• Serve as a technical partner to customers and external collaborators, supporting system‑level integration of fluid solutions into broader product architectures.
• Drive simulation, analysis, and test efforts to validate fluid flow, pressure drop, thermal performance, and material compatibility across operating conditions.
• Develop, review, and approve engineering requirements, specifications, and technical documentation in accordance with applicable industry standards and regulatory expectations.
• Lead and influence design reviews, presenting technical tradeoffs, risks, and recommendations to cross‑functional teams, customers, and senior stakeholders.
• Identify technical gaps and emerging challenges, advocate for targeted research and development, and lead exploratory efforts that build foundational knowledge and intellectual property.
• Establish and promote best practices in fluid system design, analysis, and documentation, contributing to a strong engineering culture and continuous improvement.
• Provide technical leadership, mentorship, and guidance to engineers across experience levels, supporting professional development and raising overall team capability.
• Contribute to new product innovation by evaluating emerging technologies, industry trends, and alternative architectures to drive differentiated fluid system solutions.
• Support the resolution of complex technical issues throughout the product lifecycle, including development, qualification, production, and field support as needed.

Skills

Fluid dynamics

Thermodynamics

Heat transfer

Mechanical design

Problem solving

Technical leadership

Cross-functional collaboration

Job description

JetCool, a Flex company, is seeking a Principal Thermal Mechanical Engineer in Littleton, MA to lead fluid and thermal system architecture from concept to production. You will mentor engineers, drive simulation and testing, and collaborate with customers to validate performance and compliance across data center cooling applications.

Your leadership will span design reviews, development activities, and cross‑functional execution to deliver reliable, scalable cooling solutions while advancing