functional systems engineer

We’re looking for a functional systems engineer to own the behavioral architecture and functional safety of our energy storage product. You’ll lead functional decomposition of the system, defining functions, operating states, and the transitions between them, and own the safety analyses (HARA, DFMEA) that keep the battery safe in the field.

You will work closely with the Firmware, Modeling, other internal ESS Engineering teams, and external parties such as EMS vendors, consultants, and site owners to translate system intent into derived functions and requirements that the product can be built against. You will not only define these inputs but ensure the delivered behavior matches what was specified. The ideal candidate is organized, sharp, motivated, and has the unique ability to see the big picture. This role combines systems engineering fundamentals and technical expertise to massively impact the success of the product.

What You’ll Do (Responsibilities)

• Lead functional decomposition of the BESS product: define system functions, allocate them across subsystems, and maintain functional flow block diagrams as the product evolves

• Develop and own the site and battery system Concept of Operations and use cases, leveraging them to define system functions and derived requirements.

• Create and manage system state diagrams and mode definitions, including operating, fault, and degraded states and the transitions between them

• Derive and manage lower-level requirements from system requirements and functions, with clear traceability from customer need through verification

• Engage third parties, including EMS vendors, consultants, and site owners, to solicit interface definitions and product-level requirements, and integrate them into the system baseline

• Own the Hazard Analysis and Risk Assessment for the product, including hazard identification, risk classification, and derivation of safety requirements

• Lead system-level Design Failure Modes & Effects Analysis, driving cross-functional participation and closing actions to completion

• Partner with firmware and modeling engineers to ensure behavioral requirements are implementable, testable, and correctly realized, including review of control logic against state definitions

• Support verification planning by defining how functional and safety requirements will be proven out at the system level

• Maintain behavioral architecture and functional safety documentation as the product evolves

• Bachelor’s degree in software, electrical, systems, or related engineering discipline

• 4+ years in software or systems engineering on complex electromechanical or embedded products

• Hands-on experience with functional decomposition and behavioral modeling (state machines, functional flow block diagrams, or equivalent)

• Fluency in requirements engineering: writing good requirements, deriving them across levels, and maintaining traceability

• Direct experience leading or heavily contributing to HARA and DFMEA activities

• Familiarity with functional safety frameworks (IEC 61508, ISO 26262, or UL 1973 / UL 9540A safety cases)

• Comfort working at the firmware boundary: able to read a state machine implementation and question a fault-handling path with embedded and controls engineers

• Comfort operating with ambiguous or undefined challenges

• Eligible to work in the U.S.

Preferred Qualifications

• Master’s degree in a related engineering discipline

• Battery energy storage, EV, power electronics, or other safety-critical product experience

• Experience taking a product through safety certification (UL 9540, UL 1973, or similar)

• SysML or other MBSE modeling experience

• Experience with requirements management tools (Jama, Polarion, or similar)

• Prior work in a startup or fast-moving NPI environment, * Be a Good Person: Treat everyone with respect and integrity, fostering a positive and ethical work environment.

The salary range for this role is $160,000-$230,000 with actual pay varying based on work location, experience, and skills. Our competitive benefits package includes:

• Flexible time off

• Comprehensive medical, dental, and vision coverage

• Strong 401(k) plan

• Equity opportunities

• Many great work perks

Join us to thrive in a supportive environment while making a meaningful impact in the energy sector!

Peak Energy is the first American venture to advance globally proven Sodium-Ion battery systems as the storage standard for the new era of renewable energy on a resilient grid. Sodium-Ion is cheap, readily available and safe, making it the leading contender in a rapidly evolving market.

Our leadership team is powered by decades of expertise in scaling gigawatt-level innovation at world-class companies such as Tesla, Apple, Powin, Enovix, Zipline, Solid Power, and Fluence. We are backed by strategic investment and product partners such as TDK Ventures and Eclipse Ventures.

We are a team of engineers, operators, entrepreneurs, and partners driven by a shared ambition to set the new performance standard for renewable energy and grid resilience.