During March 2026, Sadie contributed to the DaleStudy/leetcode-study repository by developing an efficient duplicate detection feature for arrays. She implemented this functionality using TypeScript, leveraging JavaScript’s Set data structure to optimize both speed and reliability in identifying duplicate values. This enhancement improved the core array utilities within the project, supporting more robust data processing and enabling future leetcode-study features to handle arrays more effectively. Sadie’s work focused on algorithm development and data structures, delivering a targeted solution to a common problem in array manipulation. Over the month, she completed this feature without addressing any bug fixes, demonstrating focused engineering depth.