Triggering Notifications Based on Enum Changes

You can use after_commit callbacks to send emails, notifications, or webhooks when an enum changes.

Example: Sending an Email When an Order is Shipped 

class Order < ApplicationRecord
  enum :status, { pending: 0, confirmed: 1, shipped: 2, delivered: 3 }

  after_commit :send_shipping_notification, if: :saved_change_to_status?

  private

  def send_shipping_notification
    OrderMailer.shipped_email(self).deliver_later if status == "shipped"
  end
end

Now, every time an order's status is updated to "shipped", an email is automatically sent.