It is a technical engineering blog post detailing turbopuffer's storage architecture evolution from v1 (vector-only SPANN/SPFresh clustering) through v2 (attribute filtering, BM25 full-text search, regex) to v3, where the ANN vector index is demoted to a secondary index. It explains problems like storage amplification, write amplification, and limited vectorization that motivated the redesign.
Most valuable when evaluating or migrating to a serverless search/vector database, architecting hybrid search (vectors + full-text + filters + aggregations), or diagnosing scaling limits like multi-vector documents and GROUP BY performance. Also useful for staying current on where vector database architecture is heading.