app.js

hamster.fetch('char:Notifications', {}, function (err, res) {
    if (err) throw err
    var notifications = res.notifications;

    // filter out all notifications w/o the right ids
    var matchingType = _.filter(notifications, function (notification) {
      return notification.typeID == 36 || notification.typeID == 37;
    });

    // convert that collection an array with just the keys
    var typeKeys = _.keys(matchingType);

    // get the cached notifications and gets an array of their ids
    var cachedNotifications = 'stuff'; // pull data from redis
    var notificationIds = _.pluck(cachedNotifications, 'Id');

    // only keep the notification id's that don't already exist
    var uniqueIds = _.difference(notificationIds, typeKeys);

    // run shit on those ids
    _.each(uniqueIds, function (id) {
      hamster.fetch('char:NotificationTexts', {IDs: id}, function(err, res) {
          if (err) throw err
          // publish the notification to all subscribers
      }
    })
})