Context precision versus context recall: which do you optimize, and how do they trade off in RAG?

Cranking up top-k raises recall but drowns the answer in noise, and a tight reranker raises precision but can drop the one chunk you needed. The signal is knowing which metric caps the system and how to move both with a retrieve-wide-then-rerank shape.

Updated Aug 2026 · Grounded in real Applied AI Engineer interview loops and written to a senior-engineer editorial bar.