customer_notification.rb

class CustomerNotification < ApplicationRecord
  belongs_to :site
  belongs_to :customer
  belongs_to :notifyable, polymorphic: true

  acts_as_tenant :site

  validates_uniqueness_to_tenant :customer_id, scope: [:notifyable_id, :notifyable_type]
end

notify_playlist_follower_job.rb

class TenantNotifyPlaylistFollowersJob < ApplicationJob
  queue_as :default

  def perform(playlist_item_id)
    @playlist_item = PlaylistItem.find_by_id(playlist_item_id)
    return unless @playlist_item.present?

    @playlist = @playlist_item.playlist
    return unless @playlist.present?

    return unless @playlist.playlist_followers.exists?

    @playlist.playlist_followers.find_each do |playlist_follower|
      @playlist_item.customer_notifications.create!(site: @playlist.site, customer: playlist_follower.customer)
    end

  end

end