Your RAG system returns wrong answers. How do you debug it?

Check retrieval first — most RAG errors are retrieval failures. Log the chunks retrieved for the failing query and ask: was the correct chunk even in the set? If not, the problem is chunking, the embedding model, or missing hybrid search. If the right chunk was retrieved but the answer is still wrong, it's a generation/grounding problem — tighten the prompt to answer only from context and cite sources. Measure retrieval (recall@k) separately from generation so you know which stage to fix.