Design and Performance Optimization of a Drone’s Lighting System This thesis reports the design, implementation, and validation of an enhanced illumination subsystem for Flyability SA’s next-generation Elios collision-tolerant indoor inspection drone, developed during a six-month internship (1 February–31 July 2026) within the R&D department as an Electronics Engineer. The Elios platform operates in confined, GPS-denied, and often hazardous environments—industrial boilers and vessels, cargo holds, underground facilities, mines, and natural cavities—where inspection feasibility depends critically on controlled on-board lighting. In such conditions, illumination is not an ancillary feature but a primary enabler for safe operation and for generating reliable inspection evidence. The work frames the lighting subsystem as an integrated engineering problem in which optical performance, power electronics, thermal constraints, mechanical integration, and verification must be addressed jointly.