Senior / Lead Cooling Systems Design Engineer

Location: Bucharest, Romania; hybrid workplace

Company

hirify.global develops AI infrastructure and modular data centres for European and US markets.

What you will do

• Take cooling equipment from initial requirements through detailed engineering, fabrication, testing, commissioning, and production.
• Translate cooling loads, ambient conditions, temperature limits, efficiency targets, noise requirements, and space constraints into engineering specifications and design margins.
• Perform heat balances, heat-transfer, airflow, hydraulic, pressure-drop, and component-sizing calculations using supplier data and realistic operating conditions.
• Design and document layouts, 3D assemblies, fabrication drawings, piping and instrumentation diagrams, refrigeration schematics, bills of materials, and technical specifications.
• Develop control sequences, sensors, alarms, interlocks, protection functions, startup, shutdown, and fault behaviour with electrical and controls engineers.
• Plan prototype testing, compare measured performance with predictions, investigate discrepancies, and improve designs for manufacturing, maintenance, cost, and repeatable production.

Requirements

• Engineering degree in mechanical engineering, thermal engineering, refrigeration, or a related discipline, or equivalent practical experience.
• Strong knowledge of thermodynamics, heat transfer, and fluid mechanics, with substantial equipment design experience in dry cooling, compressor-based air conditioning and refrigeration, or both.
• Demonstrated experience personally designing, fabricating, and successfully testing cooling systems.
• Ability to turn engineering calculations into manufacturable designs and complete, accurate documentation.
• Experience with applicable European and US requirements and cross-functional work with mechanical, electrical, controls, suppliers, and manufacturing teams.
• Proficiency with relevant calculation, equipment selection, simulation, and mechanical CAD tools; examples include REFPROP, Güntner Product Calculator, Ansys Fluent, and SolidWorks.

Culture & Benefits

• Remote-first collective with in-person meetings twice a year for planning, collaboration, and team events.
• Core collaboration hours with flexibility to manage the rest of the schedule independently.
• Fast, intense release cycles followed by dedicated downtime to recharge.
• Generous paid time off, including vacation, sick days, and public holidays.
• Meaningful stock options, paid family leave, and a remote-first setup where employment is available.