What to work through
Work through an autocomplete search box as a spoken system design interview. Start by clarifying the scope, sketch a working design and explain the trade-offs behind your choices.
- Suggest results as someone types, with no submit button
- Pick a suggestion with the mouse or the keyboard
- Show loading, no results and error states
- Let each team change how a result looks
Constraints to discuss
- Each keystroke answers within 200 milliseconds
- Usable with only a keyboard, and with a screen reader
- No request for an empty query or one under 2 characters
- Works on phones and desktop browsers
Need a starting point?
Watch for these common gaps as you prepare:
- A request on every keystroke with no pause
- No cancellation, so an older answer replaces a newer one
- Sending a request for an empty query
- Mouse only, with no keyboard support
- An active option left pointing past the end when the results change
Why this question is in the collection
These sources connect the problem to company interview reports or preparation guides. They do not guarantee what a company will ask you.
- Meta: A front end engineer reports "Design a Typeahead" as the onsite system design round, about February 2026.
- LinkedIn: A senior front end candidate reports a design round in August 2025 built around an autocomplete widget, then implemented.
- Instacart: A senior candidate reports a 60-minute onsite design round, about July 2026: the search bar with its suggestions, and the search page.
- Atlassian: A senior frontend candidate reports a technical screen in October 2026: a search input over a product catalog with no limit on results.
- Databricks: Listed by PracHub in September 2026 as a frontend engineer question, with no candidate narrative.