Performance

What the library does

• Native-driver animations. Wheel 3D transforms, fades, month slides and sheet transitions run on the UI thread on iOS and Android.
• Virtualized lists. Wheels and the emoji grid are FlatLists with getItemLayout, so only visible rows exist and scrolling never measures.
• Memoized rows. While a wheel scrolls, only the two rows whose selected state flips re-render. Calendar days and emoji cells are memoized too.
• Lazy emoji data. The 1,906-emoji table is parsed on first use and cached.
• Formatter cache. Intl.DateTimeFormat instances are cached per locale and options.

What you can do

Keep items / options stable. Define them outside the component or useMemo them. New arrays every render make wheels re-normalize their items.

// ✅ stable
const HOURS = Array.from({ length: 24 }, (_, i) => i);
function Example() {
  return <WheelPicker items={HOURS} … />;
}

Memoize theme and styles objects, especially on wheels:

const theme = useMemo(() => ({ colors: { primary: brand } }), [brand]);

Keep callbacks light. onValueChanging fires on every row crossing; do haptics or cheap updates there, not network calls. Save in onChange.

Keep isDateDisabled fast. It runs for up to 42 days per render. Precompute a Set of toDateKeys.

Mount sheets once. Keep <DatePickerSheet visible={open} … /> in the tree and toggle visible. It renders nothing while closed.

Long select lists. SelectList is virtualized. For thousands of options, give it a listHeight so the FlatList can window.