Read before using delayed jobs

delayed_jobs.md

Things to be careful about when using delayed jobs

1. Do not use delayed jobs if your system can have 100k+ jobs at a time in delayed jobs table. It'll cause the jobs to run very slow.

2. Check conditions before adding the jobs to queue, instead of checking inside the job. This'll prevent delayed jobs table from being over-populated.

   # bad
   class Order < ApplicationRecord
     after_create :send_to_webhook
     
     def send_to_webhook
       if condition?
         # code
       end
     end
     handle_asynchronously :send_to_webhook
   end
   
   # good
   class Order < ApplicationRecord
     after_create :send_to_webhook, if: :condition?
     
     def send_to_webhook
       # code
     end
     handle_asynchronously :send_to_webhook
   end