Senior Thermal Engineer: Data Center Cooling & CFD Lead

RosaicLabs Inc; Santa Clara (CA); On-site; USD 120,000 - 190,000; Full time

Benefits offered by this job

Medical insurance (including HSA)

Dental

Vision

Life & AD&D

401(k)

Job summary

Rosaic Labs in Santa Clara, CA is seeking an experienced Thermal Engineer to own the cooling design of our server solutions from concept to validation. You will develop air and liquid cooling architectures, model them with CFD, and verify results in the lab, balancing thermal performance with power and mechanical constraints.

This hands-on, cross-functional role requires close collaboration with electrical, mechanical, and packaging teams and a solid understanding of data center cooling

Qualifications

• Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or a related field.
• 7+ years of experience designing thermal solutions for servers, storage, networking, or similar high-power electronic systems.
• Proven record of taking cooling designs from concept through validation and production.
• Strong hands-on experience with CFD tools for electronics cooling.
• Experience planning thermal tests and correlating measured data with simulation results.
• Solid grasp of heat transfer, fluid mechanics, and thermodynamics fundamentals.
• Working knowledge of data center architecture, including rack layouts, hot/cold aisle containment, and facility cooling infrastructure.
• Familiarity with air and liquid cooling solutions available from industry suppliers.
• Effective communicator who works well across electrical, mechanical, and package engineering teams.

Responsibilities

• Define and design thermal solutions for servers and rack-level systems, including heat sinks, cold plates, fans, airflow management, and liquid cooling loops
• Run system- and component-level CFD simulations to evaluate design options, predict component temperatures, and guide layout decisions early in development
• Plan and execute full-system thermal chamber tests, using thermal test vehicles where needed, and correlate results against simulation models to refine accuracy
• Partner with electrical engineers on power maps, board layout, and component placement to manage hot spots
• Work with mechanical engineers on enclosure, airflow paths, fan placement, and integration of cooling hardware
• Collaborate with package engineers on die- and package-level thermal characteristics, thermal interface materials, and junction temperature targets
• Evaluate and qualify cooling solutions from suppliers (heat sinks, cold plates, CDUs, manifolds, fans), and drive technical alignment with vendors
• Translate data center requirements (rack density, inlet temperatures, airflow, facility water conditions) into server-level thermal specifications
• Develop thermal control strategies and thermal margins together with firmware and system teams
• Document design reviews, test reports, and thermal specifications, and present findings to cross-functional stakeholders

Skills

Thermal design

CFD for electronics cooling

Cross-functional collaboration

Data center knowledge

Effective communication

Education

Bachelor's degree in Mechanical or Aerospace Engineering

Tools

CFD software

Thermal testing instruments

Data acquisition systems

Thermocouples/Flow meters

IR cameras

Job description

Rosaic Labs in Santa Clara, CA is seeking an experienced Thermal Engineer to own the cooling design of our server solutions from concept to validation. You will develop air and liquid cooling architectures, model them with CFD, and verify results in the lab, balancing thermal performance with power and mechanical constraints.

This hands-on, cross-functional role requires close collaboration with electrical, mechanical, and packaging teams and a solid understanding of data center cooling