The BESS Field Service Engineer (FSE) is responsible for performing field service activities on Battery Energy Storage Systems (BESS) and associated equipment from installation/commissioning through warranty and long‑term O&M support. The FSE executes preventive and corrective maintenance, supports troubleshooting and upgrades, and works closely with Senior Field Service Engineers, site teams, subcontractors, and customers to ensure safe, high‑quality service delivery.