Design Typeahead Search
MediumSystem design · Search · Google
Design typeahead suggestions for a search box. As users type a prefix, the system returns ranked suggestions quickly.
Requirements
- Return suggestions under tight latency budgets
- Rank suggestions by popularity, freshness, and personalization if in scope
- Update suggestion data from query logs or content changes
- Discuss trie, prefix index, cache, regional replication, and hot prefixes