Our client 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.
Role Overvie
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We're looking for a Senior Product Engineer to own the technical design, specification, and continuous improvement of our BESS and DC Cabinet product lines. This is a product role at its core: you'll author technical specifications, drive vendor engagement, perform detailed component sizing, and partner with project, commissioning, and O&M teams to close the loop between field experience and product design. You should have lived through full product development cycles and know how to bring engineering discipline into a fast-moving environment with frequent release cycle
s.
What You’ll
Do
Product Definition & Specifica
- tionAuthor and maintain detailed technical specifications for the BESS and DC Cabinet — electrical, mechanical, environmental, and interface requireme
- nts.Review and approve detailed engineering drawings: SLDs, GAs, schematics, wiring diagrams, panel layouts, mechanical drawings, and BoMs. Own the technical change basel
- ine.Perform in-depth component sizing: fuses, busbars, cables, contactors, disconnects, protection coordination, short-circuit and arc-flash inputs, and thermal sizing of cabinets (forced air / HVAC, natural convection, hot-spot analysis, derati
ng).
Vendor & Supply Chain Engag
- ementLead technical engagement with key vendors — particularly on the DC Cabinet — driving specs into RFQs, evaluating vendor designs, running design reviews, and resolving issues through prototyping, FAT, and serial produc
- tion.Qualify alternate suppliers and own the technical side of dual-sourcing and cost-down decis
ions.
Product Devel
- opmentDrive iterative product development cycles with the development team, balancing speed with the rigor expected of mission-critical har
- dware.Capture design feedback from design reviews, commissioning, and O&M, and convert it into prioritized changes on the product roadmap via a structured ECR/ECN pr
- ocess.Run trade studies on architecture and component selection where it matters — cost, reliability, lead time, perfor
mance.
Project & Commercial
- SupportSupport business development with technical proposals — SLDs, GAs, and SOC analysis across multiple market applic
- ations.Compile and own the product technical information package handed to project engin
- eering.Co-lead review and validation of BESS- and DC Cabinet-related topics during project exe
- cution.Maintain as-built drawings and the engineering document ba
- seline.Participate in commissioning, particularly for first-of-kind deployments, and bring lessons learned back into the p
roduct.
Required Qualif
- ications
Bachelor's degree in Electrical Engineering, Power Electronics, or a closely related technic - al field.6+ years of hands-on engineering experience in BESS, power electronics, UPS, or comparable mission-critical / industrial power systems, with clear evidence of ownership through full product developmen
- t cycles.Proven product or system-level design experience on MWh-scale BESS or equivalent DC power e
- quipment.Demonstrated experience taking a product through the full development cycle — concept, prototype, FAT, field deployment, revision — in an environment with frequent releas
- e cycles.Strong, demonstrable skill in detailed component sizing: fuses, cables, busbars, protection devices, and thermal sizing for enclosed
- cabinets.Fluency producing and reviewing SLDs, GAs, schematics, and panel layouts; comfortable in AutoCAD or equivalent E-CAD tools and reading mechanical
- drawings.Track record of running technical vendor relationships through design, FAT, and post-de
- ployment.Excellent written communication — specs, design reviews, change notices — and the ability to translate between engineering, project, and commerci
- al teams.Willing to travel u
p to 20%.
Pref
- erred Plus
Experience with data center / UPS / mission-critical power or utility- - scale BESS.Familiarity with UL 9540 / 9540A and NFPA 855, plus the relevant codes for your tar
- get market.Experience with PLM tools and structured ECR/ECN
workflows.