Rightmove, the UK's largest property rental and sales website, transitioned from a monolithic search engine to Elasticsearch in 2014 to address scalability and functionality challenges. This shift was part of Project Odin, an internal initiative to find a more efficient search solution. Elasticsearch was chosen for its faster indexing, ease of use, scalability, and built-in features, including geo-search capabilities that were previously lacking. These capabilities enabled Rightmove to enhance its website with advanced mapping features like "Draw-a-Search" and "Where Can I Live?" tools, offering users personalized search experiences based on location and other criteria. Additionally, Elasticsearch's percolator feature allows Rightmove to efficiently match property documents to saved user queries, facilitating automatic notifications of matching properties. The transition to Elasticsearch also supports Rightmove's microservice development, enabling more frequent deployments and improving customer experience with enhanced search and reporting functionalities.