Indexing the Data Lake for Online Point Queries | Spotify Engineering

Companies like Spotify need vast quantities of data accessible at low latency for online services and, increasingly, AI Agents acting on behalf of users. Online services — such as portals and personalization features that use or display a user's listening history — need to look up and paginate through per-user data at interactive speeds. AI Agents answering questions like, "what was I listening to last summer?" need to retrieve a user's data quickly so they can reason over it — filtering, aggregating, or even running SQL locally — to build context for LLM prompts. Both patterns share the same underlying primitive: fast point queries by key over datasets that are often far too large to economically keep resident in a key-value (KV) store like Bigtable or DynamoDB.

Raccontata daengineering.atspotify.com