After years of coaching candidates and sitting on the other side of the hiring table, I've seen the same mistakes come up over and over. The frustrating thing is that most of them are completely avoidable. Here are the ones that cost people offers most often.
Not preparing specific examples. The number of candidates who walk into interviews with only vague, general answers to behavioral questions is alarming. "I'm a strong communicator" means nothing without a story that proves it. Prepare at least eight to ten STAR stories before any interview — specific situations, specific actions, specific results with numbers. Map them to the job description so you're drawing from a library of tailored evidence, not improvising on the spot.
Badmouthing previous employers. This is a trap that catches people who are genuinely frustrated with a past job. The interviewer asks "why did you leave?" and the honest answer involves a toxic manager or a dysfunctional culture. You can be honest without being negative. "I realized I wanted to be in a more collaborative environment" is honest. "My manager was a nightmare and the team was a mess" ends your chances. Every interviewer knows that if you talk this way about past employers, you'll talk this way about them eventually.
Not doing enough company research. Candidates who can't answer "what do you know about us?" or who ask questions that are obviously answered on the company's homepage signal that they're not actually that interested in the role. Spend at least two hours on company research before every interview. Know the product, the competitive landscape, the recent news, and the team you'd be joining. Have specific questions ready that show you've done the work.
Forgetting that you're also evaluating them. A lot of candidates are so focused on making a good impression that they forget to assess whether the role is actually right for them. Come in with genuine questions about the team culture, the manager's leadership style, what success looks like in the first six months. An interview where only the company is doing the evaluating is a bad interview — and a company that doesn't want to be evaluated is a red flag.
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