During November 2025, this developer contributed to the DaleStudy/leetcode-study repository by building two core array algorithm utilities in JavaScript. They implemented a Set-based function to detect duplicate values in arrays, ensuring efficient performance and including unit tests to validate correctness and prevent regressions. Additionally, they developed a Two Sum algorithm that locates indices of two numbers adding up to a target value, addressing a common problem in algorithmic interviews. Their work demonstrated solid skills in JavaScript, algorithm development, and problem solving, with a focus on code quality and test coverage. No bug fixes were recorded during this period.