I was referred by a current employee. I filled out the online application and was called in the same week. The interview itself was a little genuine getting to know each other and a lot of required questions the catering manager had to ask everyone. From what I could tell, the main objective is to make sure you're good enough at talking to people to be trusted to represent Qdoba on your own.
After the interview, I had to fill out some online agreements and provide the usual delivery driver paperwork (proof of insurance, DMV affidavit, etc). I was waiting for a week or so after that before my first shift.