Sr Manifold Engineer - Thermal & Fluid Systems

Job Posting Start Date 10-17-2025 Job Posting End Date 12-31-2025

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.

Job Summary

Join our team at JetCool , a Flex company, to help shape the future of datacenter cooling with cutting-edge technology. This is a great opportunity to work in a collaborative, mission-driven startup environment. In this role, you will make a real impact on energy efficiency and sustainability in computing infrastructure.

As a Senior Manifold Engineer in Littleton, MA, you will be responsible for designing and optimizing the fluid architecture that enables efficient and reliable cooling across our product portfolio. You'll work closely with thermal, mechanical, and manufacturing teams to develop manifolds that meet performance, scalability, and manufacturability requirements.

• Design and develop fluid distribution manifolds for liquid cooling systems used in processors, servers, racks, and datacenter deployments.
• Perform CFD simulations and thermal-fluid modeling to optimize flow uniformity, pressure drop, and thermal performance.
• Select materials and components suitable for high-reliability, corrosion-resistant, and leak-proof operation.
• Integrate and specify quick disconnects, fluid seals, and other connectors for modularity, serviceability, and long-term reliability.
• Collaborate with mechanical and manufacturing engineers to ensure designs are scalable and cost-effective.
• Support prototype builds and testing, iterating designs based on performance data and feedback.
• Create and maintain detailed technical documentation, including CAD models, drawings, BOMs, and specifications.
• Work with suppliers and contract manufacturers to validate production processes and quality standards.
• Stay informed on emerging technologies in fluid distribution, sealing systems, and datacenter cooling infrastructure.

• Bachelor's or Master's degree in Mechanical Engineering, Thermal Engineering, or a related field.
• 3+ years of experience in fluid system design, preferably in electronics cooling or industrial thermal systems.
• Proficiency in CAD tools (e.g., SolidWorks, Creo) and CFD software (e.g., ANSYS Fluent, COMSOL).
• Strong understanding of fluid dynamics, heat transfer, and thermodynamics.
• Familiarity with quick disconnects, fluid seals (e.g., O-rings, gaskets, compression fittings), cold plates, pumps, and other liquid cooling components.
• Knowledge of manufacturing processes such as CNC machining, injection molding, and brazing.
• Excellent problem-solving skills and ability to thrive in a fast-paced, iterative development environment.
• Experience designing for high-density server environments or rack-scale cooling systems is a plus.
• Experience in a startup or early-stage product development environment is a plus.
• Knowledge of ASHRAE thermal guidelines, datacenter standards, and sustainability practices is a plus.

• 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