making delayed_job perform synchronously in development

append-environment.rb

# inside config/environment.rb
if Rails.env == 'development'
  Rails.logger.info "Delayed::Job is executed synchronously in #{Rails.env} mode."
  Delayed::Job.class_eval do
    def self.enqueue(obj)
      Rails.logger.info "Delayed::Job:SYNC START"
      obj.perform
      Rails.logger.info "Delayed::Job:SYNC END"
    end
  end 
end

use Delayed::Worker.delay_jobs = false https://github.com/collectiveidea/delayed_job#gory-details