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Core
Reranking
Reranking is a two-stage retrieval design: a fast bi-encoder grabs a broad candidate set for recall, then a slower but more accurate cross-encoder rescores each (query, document) pair to reorder them for precision. The cross-encoder wins because it reads query and document jointly instead of as precomputed vectors. Reranking lets you hand the model fewer, better chunks, often the highest-ROI improvement to a RAG system. AI, ML, and GenAI interviews test it because it is the cheapest large win in retrieval quality.
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RELATED CONCEPTS
PRACTICE THIS IN REAL QUESTIONS
RAG & Agent System DesignWhat is reranking in a RAG pipeline, and why does a cross-encoder reranker improve results?→RAG & Agent System DesignDesign a production RAG system over 10M documents serving ~1,000 QPS at sub-second latency.→RAG & Agent System DesignWhat is late interaction (ColBERT), and how does it sit between bi-encoders and cross-encoders?→Coding & DSAImplement a cross-encoder reranker and prove it improves nDCG@10.→RAG & Agent System DesignHow do you choose chunk size and decide between dense, sparse (BM25), and hybrid retrieval?→RAG & Agent System DesignContext windows are now huge. When do you just stuff everything in context instead of building RAG?→
COMPANIES THAT ASSUME THIS
