How to Use Cross-Encoders for Reranking in RAG Pipelines
A practical guide to cross-encoder reranking for ML engineers building RAG systems: why bi-encoder retrieval misses relevant chunks, how cross-encoders score query-document pairs jointly, reranking with sentence-transformers ms-marco and BAAI/bge-reranker models, integrating via LangChain ContextualCompressionRetriever, latency and batching optimisation, and how to choose between open-source and hosted reranker options.