Simple Active Job example

billing_service.rb

class BillingService
  def self.process(order)
    Rails.logger.info "Processing order #{order.id}..."
    sleep(3)
    Rails.logger.info "Order #{order.id} processed successfully."
  end
end

process_order_job.rb

require './app/services/billing_service'

class ProcessOrderJob < ApplicationJob
  queue_as :default

  def perform(order_id)
    order = Order.find(order_id)
    BillingService.process(order)
  end
end