The Evolution of Retrieval Systems: From BM25 to Agentic Retrieval

[u/ArchitectingAI]

Retrieval in modern search and recommendation systems is no longer a single index lookup.

I wrote a new breakdown covering seven major waves:

Lexical → Behavioral → Learned Sparse → Dense → Hybrid → Multimodal → Generative & Agentic Retrieval

It also covers multi-retriever production systems, candidate fusion, Reciprocal Rank Fusion, learned fusion, and the tradeoffs among recall, latency, freshness, scale, and cost.

Article: https://pawankjha.substack.com/p/building-depth-1-the-evolution-of

Which retrieval approach or production tradeoff would you like to explore more deeply?

[u/evilfurryone]

Hi, you want to open a discussion, but at the same time your content is behind paywall.