Gist for the article -- https://medium.com/evenbit/making-a-firebase-server-worker-in-the-cloud-c46c37cc88f3

firebase-dataconsistency.js

  var visitsRef = firebase.database().ref('/visits');

  visitsRef.on('child_added', function (snapshot) {
      var visitData = snapshot.val();
      var visitId = snapshot.key;

      var updates = {};
      updates[util.format('/meta-data/visits/%s', visitId)] = {
          created: firebase.database.ServerValue.TIMESTAMP,
          modified: firebase.database.ServerValue.TIMESTAMP
      };
      updates[util.format('/businessVisits/%s/%s', visitData.businessId, visitId)] = visitData;
      updates[util.format('/memberVisits/%s/%s', visitData.memberId, visitId)] = visitData;

      firebase.database().ref().update(updates);
  }, function (errorObject) {
      util.error("The read failed: " + errorObject.code);
  });