How would you implement a cancellable search-as-you-type with RxJS?

Short Interview Answer

Listen to input events, debounceTime, distinctUntilChanged, switchMap to HTTP.

Detailed Explanation

switchMap cancels in-flight requests when the query changes. Handle errors with catchError per inner observable so the outer stream survives.

Example

query$.pipe(
  debounceTime(300),
  distinctUntilChanged(),
  switchMap(q => this.api.search(q).pipe(catchError(() => of([]))))
)