These are the most common mistakes I’ve seen that you need to avoid:
It is critical to keep your answers concise. You should never give more than a two-minute answer to any question. If your interviewer wants to dig deeper on anything that you mentioned, they will ask, otherwise you are wasting valuable time.
Take one or two sentences to set up your story, and then talk about what you did. If you have spent time preparing, you should already know how to set up, in a concise and interesting way, any of the stories that you will be telling.
Not Selling Yourself
The whole point of a behavioral interview is to sell yourself and show the interviewer why you’re the right person for the job. That means that you’re allowed to brag about your accomplishments here. Don’t be obnoxious about it, but don’t hesitate to confidently talk about what YOU accomplished.
One place where you may be underselling yourself inadvertently is when speaking about work that you did as part of a team. Yes, the fact that you worked with a team is important, but it’s also critical to specifically highlight your own accomplishments. Say “I” not “we” when talking about what you did.
Not Being Genuine
If you’ve ever heard someone say that their weakness is that they “work too hard” or anything like that, that’s a perfect example of something that will not seem genuine to your interviewer. You want to sell yourself, but picking something that would be considered a positive trait by many looks like you’re trying to cover up your real weaknesses.
Focus on telling real stories, and tie those stories back to what the company is looking for in an employee. If you do that, you don’t have to be perfect. No one expects you to be perfect. They want to see that you’re a human they want to work with.