What are subtle red flags at a job interview that say, "Working here would suck"?

Worked for a small mom and pop restaurant. I was the manager and was talking to one of the owners about giving a raise to someone that had been working for us forever, was constantly picking up shifts when we needed, went above and beyond every time we called on them, was basically just glue that kept us together. I could tell they were getting burnt out and thought she deserved a raise to boost their spirits. This person loved the people they worked with (not the owners) so much they'd skip class to pick up shifts if we really needed it, knowing we were pretty understaffed thanks to owners not wanting more than bare minimum amount of employees. (Note: these people were textbook examples of mom and pops taking advantage of lack of work in an area with abundant potential employees, they pretty much let everyone know how replaceable they were, even me. Overworked, underpaid, did shady shit to not have to pay overtime despite multiple people working enough hours to qualify for it. Literally never gave a raise the first couple years the place was open despite making enough to give fucking ONE PERSON a raise. I was pushing for raises for employees when I was working 70+ hours a week making <$30k before taxes.) Anyways, the boss looks at me and is like "I think we take care of our own enough as it is. Remember when I got her that meal and beer the other day?" Like he let them get a PBR and a $3 burger for free, and thought the rare instance of that happening was enough to forgo a raise. Fucking hated the business side of those people.

/r/AskReddit Thread Parent