This UX case study examines the redesign of an e-commerce mobile application aimed at improving user engagement and checkout efficiency. The project began with user research involving surveys and usability testing to identify pain points, revealing difficulties with navigation and a complex checkout process. Based on these insights, the design team implemented a simplified interface with intuitive categorization and introduced a one-step checkout feature. Post-launch analytics indicated a 25% increase in completed purchases and a 30% reduction in average checkout time, confirming the effectiveness of the design changes. This case study highlights the value of user-centered design and iterative testing in enhancing overall user satisfaction and business outcomes.