How do I SOA?

gistfile1.txt

POST file to /songs:
{
  id: UUID,
  bytes: byte[],
  title: // blah blah
  
}

express method handle POST request:
  put the POST data in the transcoding message queue with message type "encodeSong"
  
transcoding worker:
  check the queue for encodeSong messages, if found:
  send the request to AWS
  save the saga with an ID (presumably the ID of the song since it has to be unique), and a status of "Requested"
  
another express handler for the AWS responses:
  response comes in
  forward the message on to the transcoding responses message queue (it's simplest to have each worker only work on 1 message type)
  
transcoding responses worker:
    checks queue for awsEncodingResponse messages, if found:
    finds the corresponding saga
    
    if no saga found, throw an exception (because you got a response to something you apparently did not request)
    if saga already complete, do nothing (idempotency)
    
    (do whatever you do to the response)
    mark the saga with a status of Complete
    save the saga