Principal Systems Engineer, R&D

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 worlds 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, were scaling faster than the grid can, transforming power from a bottleneck into a competitive advantage for the companies building the future.

Role Objective

The Principal Systems Engineer will serve as a technical originator and design authority for new ON.energy products. This role is responsible for identifying and shaping new product concepts, leading engineering teams through preliminary design, and supporting the transition from prototype to full productization. The Principal Systems Engineer will own requirements development, drive early-stage prototyping, coordinate with supply vendors on component engineering, and apply structured qualitative decision-making to navigate the trade-offs inherent in grid-scale energy storage system design. Residing within the R&D team, this position ensures that ON.energys product pipeline is grounded in sound, agile systems engineering practice.

Key Responsibilities

Product Concept Origination

• Opportunity Identification: Monitor market signals, customer feedback, field performance data, and technology trends to identify opportunities for new products or significant architectural evolution of existing ON.energy platforms. Translate unmet needs into preliminary product concepts with clear value propositions.
• Feasibility Assessment: Conduct early-stage technical feasibility studies, evaluating product suppliers, novel topologies, and control strategies to down-select concepts before committing engineering resources. Coordinate internal and external subject matter expertise review and feedback into all evaluations.
• Concept Documentation: Author concept proposals that articulate the technical approach, target specifications, competitive differentiation, key risks, and resource estimates. Present concepts to R&D leadership and cross-functional stakeholders for stage-gate review.

Requirements Development and Management

• System Requirements Authoring: Develop and maintain system-level requirements documents that capture functional, performance, environmental, safety, and regulatory requirements for new products. Ensure requirements are traceable, testable, and aligned with customer and grid code obligations.
• Requirements Flow-Down: Decompose system requirements into subsystem and component specifications. Coordinate with discipline engineers to ensure consistent interpretation and compliance.

Preliminary Design Leadership

• Architecture Definition: Lead the definition of system architectures for new products, including power conversion topology, DC bus design, protection and isolation strategy, control hierarchy, and mechanical/thermal layout. Produce system block diagrams, interface control documents, and preliminary design packages.
• Prototyping and Early Validation: Plan and oversee prototyping activities to retire key technical risks early in the design cycle. Define prototype scope, success criteria, and test plans. Coordinate rapid-build efforts across hardware, firmware, and test teams.
• Design Reviews: Organize and lead preliminary design reviews (PDRs).

Supply Vendor Engineering Coordination

• Vendor Technical Interface: Serve as the primary engineering point of contact with component and subsystem vendors. Communicate technical requirements, review vendor design proposals, and negotiate specification compliance.
• Vendor Qualification and Selection: Lead technical evaluation of prospective vendors through design audits, capability assessments, and prototype sample testing. Provide engineering input to make/buy decisions and vendor selection trade studies.
• Supply Chain De-Risking: Align early stage reviews of supplier readiness with supply chain team.

Qualitative Decision-Making and Trade Studies

• Structured Trade Analysis: Design and facilitate trade studies that weigh product success criteria.
• Risk-Informed Prioritization: Maintain a living technical risk register for each product development program. Prioritize risk-retirement activities based on consequence and likelihood, and ensure mitigation plans are resourced and tracked.
• Cross-Functional Alignment: Facilitate decision-making across engineering, product management, operations, and supply chain stakeholders.

Productization Support

• Design Transfer: Support the transition of validated designs from R&D into product engineering.
• Production Issue Resolution: Provide systems-level engineering support during initial product deployment. Triage integration and commissioning issues, lead root-cause investigations, and implement design corrections with the help of other R&D verticals.
• Continuous Improvement: Feed field performance data and production lessons-learned back into the design process.

Experience and Requirements

• Education: B.S. in Electrical Engineering, Systems Engineering, Mechanical Engineering, or a closely related field. M.S. or Ph.D. preferred.
• Experience: 10+ years of systems engineering experience in power electronics, energy storage, or adjacent power/energy hardware product development, with demonstrated progression from individual contributor to technical leadership. Track record of taking products from concept through production release.
• Grid-Scale Energy Storage: Direct, hands-on experience with grid-scale battery energy storage systems (BESS) is preferred. Deep familiarity with BESS architectures, inverter topologies, DC system design, thermal management, and the regulatory and standards landscape (IEEE 2800, UL 9540, NFPA 855, NERC).
• Requirements Engineering: Proven experience authoring, managing, and flowing down system requirements for complex electromechanical products.
• Vendor Coordination: Experience managing technical relationships with component and subsystem vendors, including specification development, design review, and qualification testing.
• Decision-Making Frameworks: Demonstrated use of structured qualitative decision-making methods to drive design choices in ambiguous or multi-objective environments.
• Technical Communication: Exceptional ability to communicate complex systems engineering concepts to diverse audiences. Comfortable leading design reviews and presenting to senior leadership.

Work Environment

This role is based in Denver, Colorado or Houston, Texas, with regular travel between ON.energy offices, vendor facilities, national lab partners, and customer project sites to advance product development from concept through deployment.

For US-based roles - What youll 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 youll 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 recruitment@onenergystorage.com
• Benefits vary by role and location and are subject to change.