What Is A Vector Database

A vector database is a database designed specifically to store and search embeddings by similarity — it lets you ask "what stored vectors are most similar to this query vector?" efficiently at scale. ## Why this appears in interviews Ever

You'll learn how this concept slots into the production systems you'll be expected to design in interviews — the same pipelines used at Anthropic, OpenAI, Cohere, and Google DeepMind.

Includes a worked example with annotated code, the common mistakes interviewers probe for, and a glossary of the terms you'll need to use fluently.