Commissioning Engineer

ON.energy is setting the standard for large load interconnection. ON’s patented AI UPS™ is a medium-voltage UPS that serves as a firewall, protecting the data center from the grid, and the grid from the data center. With multiple gigawatts currently under construction, we are enabling grid-safe data centers. Commissioning Engineer Field Engineer / Systems Integrator — Mission-Critical Power & Energy Storage Location: Field-Based in United States (with travel to active project sites) Travel Requirement: >80% Position Type: Full-Time, Hourly (non-exempt, eligible for OT) + per diem eligible while traveling + eligibility for annual short-term incentive bonus (performance based) Reports To: Senior Commissioning Engineer 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. Overview ON.energy is seeking a Commissioning Engineer (Field Engineer / Systems Integrator) to execute system-level commissioning, lead small on-site teams, and drive project milestones across ON.energy’s mission-critical, medium-voltage double-conversion UPS deployments built on utility-scale and C&I energy storage equipment (batteries, transformers, PCS, and controls). Reporting to a Senior Commissioning Engineer, you will be trusted to operate autonomously on-site — managing testing, troubleshooting, and documentation while maintaining the highest standards of safety and quality. This is a high-travel, hands-on field role. You will spend the majority of your time on project sites across the U.S. and occasionally internationally. The ideal candidate is technically sharp, highly organized, and comfortable leading a small team in fast-paced construction environments. Key Responsibilities Commissioning & Testing • Execute system-level commissioning tests including functionality checks, network verification, and performance validation for data center, utility-scale, and C&I energy storage projects. • Support FAT validation and site acceptance testing (SAT) in coordination with OEM and owner engineers. • Perform functional testing of inverters, PCS, BMS, EMS/SCADA, protection relays, and associated BOS equipment. • Identify, document, and resolve commissioning deficiencies; manage punch lists through to closeout. Team & Project Leadership • Manage a subset of the on-site commissioning team (2–10 people), autonomously driving project initiatives as directed by the Senior…