A deep-dive into improving RAG retrieval quality using cross-encoders and reranking. Covers the architectural difference between bi-encoders and cross-encoders, the two-stage retrieval pattern, fine-tuning cross-encoders on domain-specific data (legal, cybersecurity), semantic query caching, multi-stage funnels with LLM reranking, knowledge distillation from cross-encoder to bi-encoder, and ColBERT-like late interaction. Includes latency profiling showing how ColBERT handles high QPS where cross-encoders saturate. All examples include runnable code.
Table of contents
The Retrieval ProblemThe Two-Stage PatternHow Bi-Encoders and Cross-Encoders WorkEnough theory. Let’s look at actual code.Where Does This Leave Us?Sort: