Real World Example

Amazon's search box asks for suggestions only after you pause typing (debounce). Instagram checks scroll position at most every 200 ms to load the next posts (throttle).

// debounce: search suggestions
const debouncedQuery = useDebounce(query, 400);
useEffect(() => {
  if (debouncedQuery) fetch('/api/suggest?q=' + debouncedQuery).then((r) => r.json()).then(setSuggestions);
}, [debouncedQuery]);

// throttle: load more posts near the bottom
useEffect(() => {
  const onScroll = throttle(() => {
    if (window.innerHeight + window.scrollY > document.body.offsetHeight - 300) loadMore();
  }, 200);
  window.addEventListener('scroll', onScroll);
  return () => window.removeEventListener('scroll', onScroll);
}, []);