The Elastic Stack tackles modernday observability & security demands of fastpaced searches in everincreasing data volumes. Elasticsearch, sitting at the core of the Elastic Stack, is a leading distributed search and analytics engine. In this talk, we give an overview of what makes Elasticsearch distributed, efficient and resilient both on baremetal and on the cloud. This includes an overview of advancements made in recent years. You will learn how: (a) data is ingested, sharded and replicated, (b) searches and aggregations are distributed, (c) recovery works in the event of failures. We conclude with the serverless cloud vision of Elasticsearch for unparallel scalability.