Elasticsearch has replaced Endeca as the search engine for AutoScout24's platform. Some key points: 1) Elasticsearch provided better performance, scalability, and ease of use compared to Endeca. The migration was completed within 3 months. 2) Over time, AutoScout24 has improved their Elasticsearch implementation by migrating to AWS, implementing rolling updates, and optimizing costs by using spot instances. 3) Looking forward, AutoScout24 aims to leverage new Elasticsearch features like percolator and graph capabilities.