The Trade Desk FE interview

UI Debugging Interview Question:
You are tasked with investigating an issue in a React-based search box component. The problem is that the search results sometimes display stale or outdated data inconsistently.

Background:

  • The search component fetches data asynchronously based on user input.
  • There is a race condition or a stale reference issue causing previous search results to overwrite newer ones in some scenarios.
  • The issue likely relates to how closures or asynchronous updates are handled in the component.

Objective:

  1. Debug and explain why the component is showing old data intermittently.
  2. Describe how race conditions can occur in React components when dealing with asynchronous data fetching.
  3. Implement a closure-based solution or use cancellation tokens / request tracking to ensure only the latest response updates the UI.