Design Search Ranking

Frame the Problem: The Query Changes Everything

The question: "Design search for an e-commerce site." Airbnb search and YouTube search work the same way.

It is the funnel from the last two lessons again, but one new input reshapes it: the query.

Here is the difference. Recommendations have to guess what you want from your history. Search does not have to guess. The user typed exactly what they want and handed it to you. That one change ripples through every stage that follows.

So the system has three jobs, in this order: understand the query, retrieve against it, then rank with it