Senior Structural Mechanical Engineer - Energy Infrastructure Projects

ON.energy is building the power infrastructure that makes the AI era possible. As AI demand surges past what the grid and traditional data centers can support, ON.energy provides a new class of power technology proven at gigawatt scale and trusted by the world's leading cloud and AI companies. Our systems are already deployed across 2.5 GW of hyper-scale campuses, validated by top U.S. national labs, and certified for grid-safe operation by major utilities.

With real products in the field, we're scaling faster than the grid can, transforming power from a bottleneck into a competitive advantage for the companies building the future.

ON.energy is seeking a Senior Structural Mechanical Engineer with strong experience in structural analysis and mechanical system validation to support the 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, and safety 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.

What You'll Do

* 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.

* 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.

Required Qualifications

* Bachelor's degree in Mechanical Engineering or similar technical field.

* 10+ years of 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.

* 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.

Preferred Plus

* Experience designing heating, ventilation, and air-conditioning (HVAC) systems.

* Understanding of thermodynamics and fluid flow analysis related to cooling systems.

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 mission-driven team shaping the future of clean energy

* Equal Opportunity: ON.energy is committed to equal employment opportunity and to maintaining a work environment free of harassment, discrimination, or retaliation.

* Accommodations:
If you need an accommodation during the application process, email re

* Benefits vary by role and location and are subject to change.