This paper presents the ergonomic design process of a Formula Student racecar seat using a multidisciplinary approach that integrates biomechanics, psychology, and software engineering. It systematically analyzes and applies state-of-the-art methods for the ergonomic design of the seat shell, drawing on established scientific principles and existing research. The focus is on the design strategies and methods used, including the derivation of a two-dimensional spine curvature using RAMSIS™, validated by a cockpit mockup test. This curvature was then used to generate a three-dimensional shape that was scanned and integrated into a CAD-based design workflow. The results include two seat prototypes: a 3D printed version and a carbon fiber version that was incorporated into the race car. This is followed by a comprehensive evaluation of the methods used and a critical discussion of the results.