sms_sender_job_2.rb

class SmsSenderJob < ApplicationJob
  def perform(recipient, message)
    send_sms(recipient, message)
  end

  def send_sms(recipient, message)
    # ...
  end
end

# You then notify everyone in a community with,
commnunity.users.each do |recipient|
  community   = recipient.community
  sms_credits = community.sms_credits

  if sms_credits > 0
    # this chucks the job to a queue and runs it asynchronously
    SmsSenderJob.perform_later recipient, 'Everything is fine. This is fine.'
    community.update_attributes!(:sms_credits, sms_credits - 1)
  end
end

# PS: This is still pretty scrappy. Do not copy.