Motorsport applications demand highly efficient, compact, and reliable power conversion systems capable of withstanding extreme dynamic conditions. This study focuses on the design and evaluation of a custom inverter tailored for a race electric motorcycle, with the objective of optimizing performance, thermal behavior, and component reliability under mission-specific constraints. The hardware design process involved selecting suitable power devices, optimizing printed circuit board (PCB) layout for minimal parasitics, and integrating a compact cooling solution. A detailed thermal model was developed to predict temperature profiles under typical racing conditions. Additionally, a reliability assessment was conducted based on real mission profiles, with lifetime estimations performed for metal-oxide-semiconductor field-effect transistors (MOSFETs) using stress data extracted from simulations. The results show that by aligning the inverter design with the actual usage profile, it is possible to significantly reduce the overall system size and cost while maintaining the required performance and ensuring component lifetimes compatible with racing demands.