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Learning path · Embeddings & Representation · 35

Embeddings

Dense vector representations of text (or other modalities) where semantic similarity approximates geometric closeness.

Why it matters

  • Foundation of semantic search, RAG retrieval, and clustering.
  • Choice of embedding model affects recall on domain jargon.
  • Separate from generative LLM—you often use both.

Key ideas

  • Vector representations
  • Similarity search
  • Domain adaptation

Embeddings map sentences or documents into fixed-length vectors optimized so related meanings sit nearby. They power "find passages like this question" without keyword overlap. Pick models trained on text similar to your corpus; legal, medical, and code domains often need specialized embedders. Re-embed when you change models—vectors are not portable across unrelated embedding spaces. Version embedding models in index metadata and block silent cross-version queries that return nonsense similarity scores. Ship only after eval gates pass on representative production failures.

Updated 2026-08-09 · Full learning path