Jetcool A Flex Company

AI and high-performance computing

Sr.ThermalSystemsEngineer

$127–127k Littleton, Massachusetts, United States FULL TIME
Market Sentiment
HIGH DEMAND

Neural analysis suggests this role is
optimal for Senior candidates.

The Brief

“Sr. Thermal Systems Engineer at Jetcool A Flex Company. Skills: Thermal Systems Engineering, Liquid Cooling, Direct-to-Chip (D2C) Cooling Systems, CFD Modeling, Thermal Analysis, Product Development. Own the end-to-end architecture, analysis, validation, and deployment of direct-to-chip (D2C) cooling systems. Define system-level thermal requirements (TDP range, ΔT, coolant temperature, flow rate, pressure drop, acoustic & power budgets)”

Industry & Context.

AI and high performance computing
Problems you'll solve

tackling complex challenges; Drive failure analysis and corrective actions (FMEAs, 8D/PPS)

What They're Looking For.

Must Have

BS/MS in Mechanical Engineering or Aerospace Engineering or related field, 5+ years experience in thermal design/validation for high-power electronics (preferably data center/server/HPC), Excellent first principles knowledge in fluid dynamics, thermodynamics, and heat transfer, Proven expertise in liquid cooling, including CFD, pressure drop/flow modeling, and thermal metrology, Hands-on with lab instrumentation (flow meters, pressure transducers, thermocouples/RTDs, DAQ, leak detectors) and test automation (Python, LabVIEW, or similar), Experience bringing products from EVT → DVT → PVT → ramp, including DFX and supplier engagement, Excellent technical communication and documentation skills

Nice to Have

PhD a plus

What You'll Do.

Own the end-to-end architecture

and deployment of direct-to-chip (D2C) cooling systems

Define system-level thermal requirements (TDP range

acoustic & power budgets)

Apply first principles in fluid dynamics and heat transfer to analyze design concept thermal performance

Build and validate 1D/3D models for cold plates

quick-disconnects (QDs)

Perform sensitivity trade-offs (flow distribution

microchannel optimization

Specify and refine cold plates

Define DFX (DFM/DFA/DFT)

Lead EVT/DVT/PVT from prototypes to mass production

Develop test plans for thermal performance

long-term reliability (HALT/HASS)

and contamination control

Execute lab and rack-scale testing

Drive failure analysis and corrective actions (FMEAs

Support manufacturing process development (leak/pressure test stations

cleanliness criteria)

Engage with customers: define requirements

analyze fleet telemetry

and support deployment at scale

How You'll Work.

Team & Collaboration

Partnering with Product Management, Mechanical/Electrical Engineering, Manufacturing, Quality, Reliability, and key customers; Collaborate with ME/EE on mechanical stack-up, materials, corrosion mitigation (galvanic compatibility), and leak risk reduction; Work with Product Management on PRDs, roadmaps, and business cases; Support manufacturing process development and supplier selection/qualification; Engage with customers

Communication Scope

Excellent technical communication and documentation skills

Process & Methodology

lead EVT/DVT/PVT from prototypes to mass production, drive failure analysis and corrective actions

Full Job Description

Job Posting Start Date 05-11-2026 Job Posting End Date 07-24-2026 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 **Senior Thermal Systems Engineer** located in**Littleton, MA.** Reporting to the**Product Manager** the **Senior Thermal Systems Engineer** will own the end-to-end architecture, analysis, validation, and deployment of direct-to-chip (D2C) cooling systems used to cool high-TDP CPUs/GPUs/accelerators. They will be the technical leader partnering with Product Management, Mechanical/Electrical Engineering, Manufacturing, Quality, Reliability, and key customers to deliver robust, scalable products that meet performance, reliability, and cost targets. **What a typical day looks like:** Own thermal architecture & modeling * Define system-level thermal requirements (TDP range, ΔT, coolant temperature, flow rate, pressure drop, acoustic & power budgets). * Apply first principles in fluid dynamics and heat transfer to analyze design concept thermal performance * Build and validate 1D/3D models (e.g., FloEFD, Icepak, MacroFlow, ANSYS Fluent, COMSOL) for cold plates, manifolds, quick-disconnects (QDs), pumps, and CDUs. * Perform sensitivity trade-offs (flow distribution, fin geometry, microchannel optimization, TIM selection, manifold topology). Design liquid cooling subsystems * Specify and refine cold plates, CDUs, manifolds, hoses/QDs, reservoirs, filters, senso

Free ATS check

Applying for this Sr. Thermal Systems Engineer role?

Most applicants get filtered before a human reads their resume. See if yours makes the cut.

How to Apply on Workday

  • Workday has a multi-step form — save your progress after every section.
  • "Apply With LinkedIn" can fail or lose data; manual entry is more reliable.
  • Watch for the "Submit for Review" final step — hitting "Save" alone does not submit.
  • Job requisition numbers are useful when following up with HR by email.

ANONYMOUS · UNFILTERED

What do employees actually say about Jetcool A Flex Company?

Real rants from real employees. Read before you apply.

Read Company Rants →