Zen Reranker: Two-Stage Retrieval Done Right
Embedding-based retrieval is fast but imprecise. Cross-encoder reranking is precise but slow. The combination unlocks the best of both. Today we release the Zen Reranker, purpose-built for two-stage retrieval. Two-Stage Retrieval Modern retrieval pipelines typically operate in two stages: Query -> [Embedding Retrieval] -> Top-K Candidates -> [Reranker] -> Final Results (fast, approximate) (slow, precise) Stage 1: Bi-encoder embeddings enable fast approximate search over millions of documents. Retrieve top-100 to top-1000 candidates....