This question evaluates understanding of search system architecture, including indexing, querying, and sharding strategies, and measures competency in designing scalable, low-latency data pipelines; it falls under system design and distributed systems and emphasizes practical application-level architecture rather than purely conceptual theory.
Design a search service that lets users query documents/products with keywords.
GET /search?q=...
returns top results ranked by relevance.
No need to write production code, but be concrete about components and data flows.