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AGT.06.02 Mid-levelCore — asked often

Retrieval basics: chunking, embeddings and vector search

Comes up in: AI engineering, AI system design

This concept is being written. It gets the full five steps — explanation, predict, interview angle, practice with tests, and review cards. Here is exactly what it will cover, so you can study it elsewhere in the meantime.

What it covers

  • RAG idea (Lewis et al. 2020)
  • ingestion
  • chunking strategies (size, overlap, structure-aware)
  • metadata
  • vector databases/indexes (pgvector, Cloudflare Vectorize, others — awareness)
  • approximate nearest neighbour (HNSW idea)

Words you will know

RAGchunkingvector indexANN

What you will practise

  • index the site's own lessons and query them

Interview questions this answers

  • How do you choose a chunk size?
  • How do you evaluate a RAG system?