I have been working at In-N-Out Burger part-time (More than 10 years)
Free food, good benefits, fun environment, flexible schedule
Depending on the region you are working in, upward advancement may not be possible, there are limited stores to work at and management positions available.
The process took 3+ months. I interviewed at In-N-Out Burger (Irvine, CA (US)).
2 months after I applied on their website, I had a 30-minute call from a recruiter. 1 week later, I had a 30-minute call with the hiring manager. 1 month after that call, I was told that they chose another candidate. All in all, this was a 3 month process that also included a 2-week vacation for the recruiter. I think that pretty much says it all.