Kara  Goldin, the founder and CEO of Hint Water, has hustle in her blood. After graduating from college, Goldin was desperate to work in the magazine business. But the response she got from editors and their assistants was only mildly encouraging: "We don't have anything now, but let us know if you're in the area and we could meet."

Goldin decided to be in the area. In a single month, she traveled to Los Angeles, San Francisco, Chicago, Boston, and New York, sleeping on friends' couches and racking up more than 90 interviews. She prepared thoroughly for each one. Invariably, at some point, the interviewer would ask Goldin what brought her to town. "People were amazed that a 21-year-old would invest in that way," she says.

So Goldin expects candidates for positions at Hint to make an investment, too. Here's what she expects to see in interviews, and how she finds the best hires for her fast-growing 100-person company.

1. Represent the brand.

No, you're not hired at Hint, not yet. But when people who walk into an interview at Hint show up drinking a Diet Coke, "It's like, did they get the memo?" says Goldin.

Her company's entire mission is to get people to stop drinking heavily sweetened beverages. An important turning point in her own personal health is when she stopped drinking a dozen cans of Diet Coke every day. "These are senior roles we're hiring for, and they're going to be representing the company," says Goldin.

Goldin understands that if you're interviewing at Tesla, you can't necessarily drive up to the interview in a Tesla. But Hint? "I've just been amazed that so many people don't try it or drink it here before the interview," she says. "The people that have no experience are more likely to go and show their enthusiasm for the product. They're hungrier, compared to the more experienced people that can be a little lazier."

2. Dress appropriately.

This is a minefield for any job candidate, but especially for women. Goldin says if you're being sent on an interview by an executive recruiter, it's fine to ask the recruiter how you should dress. Failing that, she suggests scouring LinkedIn for a connection that knows Hint, and asking them for advice.

If you're still in doubt, says Goldin, it's better to dress up than down. That way, if you show up to the interview and you're obviously overdressed, you can still recover. A line such as, "I don't usually dress up this much, but I had a meeting before yours that was much more formal," will usually do the trick, says Goldin. "If you're in your workout shirt, it's a bit tougher."

3. Ask how you can be successful.

Goldin says she absolutely loves it when someone asks how they can be successful at Hint. "It shows they're ready to hit the ground running and really do something to move the needle," says Goldin. Candidates who ask this question appear to be in the mindset of, "What can I do to help?" rather than, "What are you guys going to do for me?" Of course, if you get an offer, it's perfectly acceptable to ask, "What are you guys going to do for me?" --albeit in a slightly different way.

Similarly, when Goldin asks candidates "Why Hint?" she's astonished when they turn around and say, "You tell me, why Hint?" Again, you might find a more polite way to ask that later in the interview. But first Goldin wants to know that you can solve problems and that you'd be excited to be on board.