ABOUT BASE Base is America’s next-generation power company. We’re rebuilding the foundation of modern civilization–electricity–by deploying a vast network of distributed batteries that is transforming today’s fragile, centralized grid into a resilient and abundant system. We are engineers, operators, and creatives solving some of the most complex, interdisciplinary challenges of our time. ABOUT THE ROLE We are seeking a Thermal Design Engineer to own thermal management for high-power-density electronics and other thermally demanding systems. This person works from first principles—pairing deep heat-transfer intuition with simulation, hand calcs, and real hardware testing—to design cooling solutions that are quiet, reliable, and effective. They own air cooling and heat-sink design as the core of the role, with active cooling (liquid loops, vapor compression) and the NVH behavior of pumps and fans as key parts of the job.   What You’ll Do * Thermal Design: Own the thermal architecture and design for high-power-density systems—from first-principles analysis through detailed design, validation, and hardware bring-up. * Heat Sink & Air Cooling: Lead air-cooling and heat-sink design across the full range of technologies (extruded, skived, bonded-fin, vapor chambers, heat pipes), selecting and sizing the right approach for each application. * Analysis & Correlation: Use CFD and thermal FEA as one tool among several—always paired with hand calcs, first-principles reasoning, and test correlation. Simulation supports the design; it is not the whole job. * Fans & Pumps (selection, test, NVH): Select, characterize, and test fans and pumps—understanding what drives their performance, reliability, and acoustic/NVH behavior, and designing to keep systems quiet. * Active Cooling: Apply vapor-compression and liquid-loop cooling where needed, including the relevant psychrometrics and refrigeration fundamentals. * CAD: Develop thermal designs in CAD and work with mechanical engineers to carry them into production hardware (production part design is not the primary focus). * Test & Validation: Build test setups to characterize thermal performance and acoustics, and validate designs against first-principles predictions.   What You'll Bring * 4+ years in thermal design for electronics or other thermally demanding systems. * Expert-level heat transfer—strong first-principles command of conduction, convection, and radiation, with excellent physical intuition. * Strong first-principles thermodynamics, including psychrometrics. * Broad, deep familiarity with heat-sink technologies and when to use each. * Proficiency with CFD and thermal FEA, with the discipline to pair simulation with hand calcs and test data rather than relying on it alone. * Strong working knowledge of vapor-compression refrigeration. * Hands-on experience selecting, testing, and characterizing fans and pumps, including their NVH behavior—what makes them loud and how to quiet them. * CAD proficiency; able to develop and communicate thermal designs (production part design optional). Preferred Qualifications: * Experience optimizing high-volume testers for cycle time and throughput. * Familiarity with test data infrastructure and databases for storing and analyzing production results. * Experience implementing and interfacing a variety of sensor types in a test context. * Background reducing false-reject rates and improving yield through measurement and fixture improvements. * Experience standing up testers quickly for prototype or early-production builds. * Strong communication skills and a track record of cross-functional work with hardware, firmware, and manufacturing teams. * Experience with acoustic/NVH measurement and mitigation in air-moving systems. * Experience designing liquid cooling loops (cold plates, pumps, heat exchangers). * Experience taking thermal designs from concept through test correlation and production. * Familiarity with high-heat-flux electronics cooling. Please note: Base is a startup, which means priorities shift and evolve quickly. Your role may expand or change based on the needs of the business at any given time, so the responsibilities listed may not be exhaustive. OUR VALUES * First Principles Thinking: Question assumptions. Principles > rules. * Operate at Base Pace: Focus on what matters, act quickly, and learn by doing. * Give & Get Feedback: Be direct, be humble, and maintain a growth mindset. * Everyone’s an Owner: Follow through on commitments and own results. * Strong Opinions, Loosely Held: Drive clarity and make calls with imperfect information. * Committed to the Mission: Rebuilding the grid is a big challenge. We work hard because we care deeply about the impact we’re creating. We work in-person. It’s not a 9-to-5. We are all-in. * Fun & Optimism Coexist with Grit: Collaboration and celebration coincide with the intensity of building real things. DO THE BEST WORK OF YOUR LIFE AT BASE.