This study investigates the impact of big data on university libraries in Bangladesh, focusing on areas such as resource accessibility, decision-making, user experiences, academic research and information management. By conducting interviews with 21 library professionals and employing thematic analysis, the study reveals critical insights. Big data significantly enhances resource accessibility by enabling customized collections and supports user-centric decision-making in library operations. It also improves user experiences through personalized recommendations and seamless navigation. Moreover, big data's analysis of citation patterns and collaborative networks bolsters academic research while addressing information overload and optimizing information retrieval processes. This research provides a thorough examination of big data's practical implications in university libraries, offering valuable insights for professionals, researchers and policymakers. It emphasizes the necessity of a proactive approach to leveraging big data's transformative potential in knowledge management, thereby shaping the future of academic libraries.