Mid-level interview questionAsked by candidates · YouTube
Why combine keyword and embedding search, and where does a reranker fit?
Model answer
Embeddings catch paraphrases; keyword search such as BM25 catches exact terms like product codes, names and error messages. Hybrid search runs both and merges the rankings, for example with reciprocal rank fusion. A reranker, a cross-encoder that reads the query and a passage together, then rescores the top few dozen: too slow for the whole corpus, much sharper on a shortlist.
Practise the rest
22 RAG questions, 492 in all, each with a model answer. Free.
More RAG interview questions
- What is retrieval-augmented generation, and how does it reduce hallucination?
- How do you choose a chunking strategy for RAG?
- How do you evaluate a RAG pipeline?
- Your RAG chatbot keeps giving wrong answers. How do you find out why, and fix it?
- Design a RAG system that has to meet strict latency and cost targets while serving many tenants.
- Design an agent for searching internal documents that respects permissions, cites sources and abstains when it should.