Staff Mechanical Engineer - Data Center Cooling

Lambda, The Superintelligence Cloud, is a leader in AI cloud infrastructure serving tens of thousands of customers. Our customers range from AI researchers to enterprises and hyperscalers. Lambda's mission is to make compute as ubiquitous as electricity and give everyone the power of superintelligence. One person, one GPU. If you'd like to build the world's best AI cloud, join us. *Note: This position requires presence in our San Francisco or San Jose office location 4 days per week; Lambda’s designated work from home day is currently Tuesday. What You’ll Do Own cooling-system standards and reference architectures for large-scale AI data centers. Design the complete thermal path from GPU and rack heat capture through facility distribution and final heat rejection. Translate server, rack, and cluster requirements into coolant temperature, flow, pressure, water-quality, and facility-capacity requirements. Develop air-cooled, liquid-cooled, and hybrid cooling architectures for greenfield, retrofit, and partner-operated facilities. Design central plants, technology cooling-water loops, CDUs, heat exchangers, pumps, piping, chillers, cooling towers, dry coolers, and adiabatic systems. Perform thermal, hydraulic, pressure-drop, heat-transfer, psychrometric, and equipment-capacity calculations. Evaluate system performance across site climate conditions, compute-load changes, equipment failures, and maintenance scenarios. Develop and review P&IDs, equipment schedules, layouts, specifications, sequence of operation, and basis-of-design documents. Define requirements for redundancy, thermal ride-through, failure isolation, maintainability, efficiency, and water consumption. Establish requirements for coolant chemistry, materials compatibility, filtration, flushing, cleanliness, leak detection, and fluid management. Review partner designs, vendor submittals, equipment selections, and construction documents for compliance with Lambda standards. Coordinate cooling interfaces across hardware engineering, electrical engineering, controls, construction, commissioning, and operations. Support equipment testing, construction sequencing, commissioning, cooling-system bring-up, and initial GPU loading. Investigate thermal events and cooling failures, incorporating lessons into future designs and operating standards. Travel to project sites, manufacturers, and partner facilities as needed. You Have experience designing cooling systems for data centers, mission-critical facilities, central plants, or large industrial environments. Understand hydronic design, heat transfer, pumping, heat exchangers, chilled-water systems, and heat-rejection equipment. Have experience with direct-to-chip liquid cooling, CDUs, technology cooling-water loops, or other high-density cooling systems. Can develop and review P&IDs, equipment specifications, mechanical layouts, and engineering calculations. Can model system capacity, flow, pressure loss, temperature approach, and performance across varying operating conditions. Understand cooling-system redundancy, failure domains, thermal ride-through, maintainability, and operational risk. Understand the relationship between GPU behavior, rack density, coolant conditions, and facility cooling capacity. Can balance reliability, efficiency, water consumption, equipment cost, and delivery schedule. Communicate clearly across engineering, construction, operations, equipment vendors, and executive stakeholders. Hold a bachelor’s degree in mechanical engineering or equivalent practical experience.

Experience designing cooling for hyperscale, colocation, HPC, or AI data centers. Experience supporting multi-megawatt liquid-cooled GPU deployments. Experience with warm-water cooling, water-side economization, dry coolers, or adiabatic heat rejection. Familiarity with CFD, Pipe-Flo, AFT Fathom, Revit, or comparable engineering tools. Knowledge of coolant chemistry, glycol systems, corrosion control, filtration,