Design a web search engine: the system design interview walkthrough The request to design a web search engine sounds impossibly large — "build Google" — and that size is exactly the trap. The sentence hides three separate systems: a crawler that discovers pages, an indexer that turns them into something searchable, and a serving layer that answers a query in the blink of an eye. A strong candidate says that out loud in the first minute, scopes the crawler to its own problem, and name...