This Manager’s Guide details the process of modernizing enterprise search by migrating from Elasticsearch to Vespa.ai, emphasizing Vespa's advantages in performance and cost-effectiveness. The guide outlines key considerations for organizations, including competitive advantages of Vespa over Elasticsearch, particularly in the context of Retrieval-Augmented Generation (RAG) and vector databases. It explains how Vespa's real-time availability, fine-grained scalability, and efficient data handling provide significant business benefits. The document presents benchmarks that demonstrate Vespa's superior efficiency, including its ability to handle more queries per CPU core and apply real-time updates faster than Elasticsearch. Additionally, it discusses Vespa's capabilities in supporting AI-driven applications, highlighting its native support for tensors and mixed data structures, which enhance real-time personalization and recommendation systems. The guide serves as a comprehensive resource for organizations seeking to leverage modern best practices in enterprise search.