With the development of additive manufacturing technologies, designers are being offered new opportunities that are changing their usual design rules. The ability to create increasingly complex shapes constitutes the main opening. The complexity achieved makes it possible to obtain lightweight parts while maintaining high mechanical performance. As a result, design methods have to be adapted. Most of these methods include a design optimization phase to improve mechanical performance. Topological optimization tools are becoming essential to achieve this objective. They allow to achieve the best possible design as unnecessary material is stripped away leaving only that needed to meet the design requirements. Nevertheless, the designer continues to play a significant role in terms of the final design owing to the number of variables and settings involved in each stage of the design process. This paper uses a case study to assess the impacts on part geometry of the different design optimization settings used in the additive manufacturing process. It highlights how the settings adjustments made by the designer have a significant impact on the final design.