Airbnb
RAG and search

CASTLE: training natural language search before the first real query

Our short summary of Airbnb’s engineering write-up. The full story, with all the detail, is on their blog.

Read the full write-up on medium.com (opens in a new tab)

Problem

Airbnb needed natural‑language search but had no real user queries or relevance labels to train on.

Solution

They created CASTLE, a system that synthesises realistic search queries and relevance labels from booking data, then trains a retrieval model on this joint synthetic data.

Want the architecture, code and numbers? They’re in the original post.

Read the full write-up on medium.com (opens in a new tab)

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