Critical app data is persisted across app lifecycle

Persisting only an auth token while leaving user profile, form progress, and app state in memory creates a class of silent data loss that frustrates users and erodes retention. When the OS terminates your app — which happens routinely on low-memory devices — anything not written to storage is gone. ISO 25010:2011 reliability.recoverability requires that at least three critical data categories survive an unexpected termination. Apps that fail here force users to repeat onboarding flows, re-enter form data, and lose context — all of which correlate directly with abandonment.

Use an AppState listener to flush state to storage whenever the app moves to the background, and restore it on foreground return. Wrap both paths in try/catch so corrupted storage doesn't crash startup.

import { useEffect, useRef, useState } from 'react';
import { AppState } from 'react-native';
import AsyncStorage from '@react-native-async-storage/async-storage';

export function usePersistState<T>(key: string, initial: T) {
  const [state, setState] = useState<T>(initial);
  const appState = useRef(AppState.currentState);

  useEffect(() => {
    const sub = AppState.addEventListener('change', async (next) => {
      if (next.match(/inactive|background/)) {
        await AsyncStorage.setItem(key, JSON.stringify(state));
      } else if (appState.current.match(/inactive|background/) && next === 'active') {
        const saved = await AsyncStorage.getItem(key);
        if (saved) setState(JSON.parse(saved));
      }
      appState.current = next;
    });
    return () => sub.remove();
  }, [state]);

  return [state, setState] as const;
}

Apply this hook to every critical data category: user profile, navigation state, and any in-progress form inputs.