The Walcraft Cabinetry case study presented a significant challenge in transitioning from an outdated kitchen CAD software, ProKitchen, to a new, cutting-edge, and user-centered proprietary CAD software using Unreal Engine 5. The Empathy phase highlighted usability issues with ProKitchen, such as hindering efficiency and incurring high user license costs. The goal was to transform the kitchen design workflow by replacing ProKitchen with a more efficient and cost-effective solution that integrates seamlessly with supplier catalogs. The Investigating phase delved into user pains, product team frustrations, and the shortcomings of previous UI designs. Research concluded that while Walcraft designers were adept at using CAD software, ProKitchen suffered from information architecture issues, too many customization options, and lacked effective project tracking and development methods. The Conceptualization phase involved user-driven iterations, card sorting, tree tests, and low to mid-fidelity prototypes, resulting in a Figma prototype that underwent rapid usability testing for continual improvement. In the Design phase, a comprehensive component library was crafted using Atomic Design principles, leading to the development of over 40 icons, 80 cards, and modular elements. The benefits of methods such as card sorting and tree tests were evident in improved navigation and user task completion rates. The Atomic Design StyleGuide facilitated faster UI tweaks, replication, and standardization, ultimately resulting in a positive user response to the new style guide's neutral and sophisticated aesthetic. After nine months, the project exhibited improved tracking, easier asset export for Unreal Engine UI development, positive user feedback, and continuous testing on Unreal Engine for complex interactions. The next steps include further design development, user testing, and refining hover states, culminating in the design of the prototype home section.