parallel-async-await.js

// API
router.get('/words', async (req, res) => {
  const wordsRef = db.ref(`words`).once('value');
  const usersRef = db.ref(`users`).once('value');
  const values = await Promise.all([wordsRef, usersRef]);
  const wordsVal = values[0].val();
  const userVal = values[1].val();
  res.sendStatus(200);
});