So you’ve gotten an interview for an internship at a startup — congratulations! Read on to learn the most common mistakes candidates make and how to avoid them.

They’re casual, but you shouldn’t be.

Startups are known for having a casual look and feel. Don’t let yourself think, though, that casual means you can come to the interview wearing a T-shirt and jeans or the equivalent. Dress to impress — jacket and tie, professional dress and heels. Dressing well shows that you take the opportunity seriously.

Showing up early is almost as bad as showing up late.

Interviewing is not like going to the doctor’s office, where it may make sense to show up half an hour early, just in case. While it goes without saying that you should never be late for an interview, it’s almost as disruptive to arrive too early, especially at smaller startups that may not have a dedicated lobby area. Your interviewer will either feel pressured to see you ahead of schedule, or you’ll be awkwardly waiting in public for some period of time. Aim to show up about five minutes before your appointment. If you arrive at the location earlier, just wait outside and go up a few minutes early.

Startups want interns who demonstrate passion for the company.

Startup employees and founders are driven by passion and deep commitment. They also want to know that you care about the company and its product or service. If the company has an app, you should have already downloaded and familiarized yourself with it before the interview. Your interviewer may ask you to open it on your phone during your chat!

If the startup sells a product and you can easily purchase a sample, then do so before the interview. Follow the company’s Facebook, Instagram, and Twitter accounts, and read up before the interview. Do a last-minute news search on the morning of your interview — your interviewer will be impressed if you exhibit up-to-date familiarity with the company.

Do your research about both the company and the competitive landscape.

You know that you need to research the startup, but be sure to familiarize yourself with its competitors and market, as well. If, for example, you’re interviewing with Uber, you should certainly also know about Lyft, Sidecar, Hailo, and Car2Go. If you don’t, your interest in the company may come across as superficial.

Startups are tight-knit groups, so show a little personality.

You’ve likely been studying the correct answers to questions about your weaknesses (yes, we know, you’re too organized and fastidious) and how you’re seeking growth and learning opportunities. That’s all well and good — but don’t be thrown when your interviewer wants to know which blogs, websites, or books you read for fun. You may have heard of something called the “airport test," where management consultants try to assess whether they’d be able to tolerate being stuck at the airport for a few hours with a potential hire.

Startups are similar because they have such a tight-knit culture. That doesn’t mean you should be unprofessional — this isn’t the time to discuss a recent bout of food poisoning — but don’t resort to canned assertions that you only read The Wall Street Journal and TechCrunch. If your interviewer can’t get a sense of what you’d be like to work with, he or she may take a pass. Describe some personal interests — companies want to know that you share their passion and that you have some of your own.

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