Vespa is an open-source big data processing and serving engine used for real-time computations over large datasets. It shines in applications that require personalization and recommendations, such as search, recommendation, ad tech, and natural language processing tasks. Vespa allows you to respond to queries by using machine-learned models in real-time at scale. What sets it apart is its ability to rank and organize data in real-time based on user queries and preferences, enabling personalized experiences. Vespa supports efficient serving of machine-learned models, making it a valuable tool in deploying AI-driven applications.