Senior Mechanical Engineering Manager

ON.energy is building the backbone of energy and AI infrastructure powering grid-safe data centers and mission-critical facilities. The company supplies and operates hyperscale power systems that solve the toughest resilience challenges, delivering custom solutions for AI data centers, mission-critical facilities, and front-of-the-meter assets. ON recently announced a 5GW partnership, with 3GW currently under construction across multiple hyperscale data center campuses. With patented technology and proprietary software, ON.energy develops projects worldwide that set new benchmarks for resilience. We are seeking a Senior Mechanical Engineering Manager with strong experience in structural analysis and mechanical systems validation to lead the mechanical design activities for the products deployed for our energy infrastructure and mission-critical projects. This is a product focused role—we need someone who can speak fluently about ensuring the structural integrity, mechanical reliability, safety and validate the thermal performance of equipment and supporting structures under static and dynamic operating conditions, ideally have experience with mission critical applications, and interface with project, commissioning and O&M engineering teams. Key Responsibilities: Perform structural stress and fatigue analysis for mechanical assemblies, enclosures, and supporting infrastructure used in ON.energy’s product offering. Lead and/or review Finite Element Analysis (FEA) models or reports to validate mechanical designs under static, dynamic, thermal, and seismic loading conditions. Ensure mechanical and structural safety under operational loads, transportation loads, vibration, and environmental conditions. Evaluate failure modes and recommend design improvements to enhance durability, reliability, and lifecycle performance. Collaborate with BESS, Power Electronics and Controls teams to ensure integrated system performance. Support development and review of mechanical documentation including calculations, reports, specifications, and as-built drawings. Experience designing heating, ventilation, and air-conditioning (HVAC) systems. Overall have experience with thermal design of enclosures e.g. calculations of HVAC, identification of temperature limits, humidity management and mitigation. Participate in product design sprints with the development team. Provide technical input during product design iterations based on lessons learned from project engineering design, installation, commissioning, and operations. Project management skills. Excellent communication skills across technical and non-technical teams. Willing to travel up to 20% for product FAT inspection and site commissioning witnessing. Required Skills & Experience Bachelor’s degree in Mechanical Engineering or similar technical field. 15+ yearsof hands-on structural and mechanical engineering experience in project-based or industrial settings. Strong experience performing stress analysis, fatigue analysis, and vibration assessment. Demonstrated experience ensuring structural safety and compliance with applicable engineering standards and codes. Ability to interpret engineering drawings and develop detailed reports and calculations. Preferred Experience: Experience with Power Electronics, UPS/mission critical applications or utility-scale infrastructure where mechanical system are applied. Panel building mechanical design experience for power and controls/IT equipment. For US-based roles - What you’ll get: Competitive salary + annual performance-based bonus eligibility Medical, dental, and vision insurance 401(k) with company match Paid time off and company holidays For Mexico-based roles - What you’ll get: Competitive salary + annual performance bonus eligibility Christmas Bonus (Aguinaldo): 30 days Major medical expenses and life insurance Paid time off and holidays (per local policy) For all roles: Professional development and growth opportunities Opportunity to grow with a m…