Pattern
Elasticsearch
Provide the original Elasticsearch implementation under Elastic's licensing, with first-class support for the full hybrid retrieval stack: BM25, dense vectors, ELSER learned sparse retrieval, RRF fusion, and the broader Elastic Stack (Kibana, Logstash, Beats, observability) for operational visibility.
Classification — Dominant enterprise hybrid search engine with ELSER learned-sparse and dense vectors.
Full entry
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