A hiring expert with 20 years of experience claims that job-seekers often overlook a "very basic" aspect during interviews.

In her 20 years in the recruiting industry, Adriane Schwager has interviewed thousands of individuals and hired hundreds.

GrowthAssistant CEO and co-founder Schwager advises that people at any experience level should show up prepared for interviews.

"Schwager tells CNBC Make It that he is surprised at how often people do not complete their homework. He emphasizes the importance of understanding the company being interviewed for, which is a basic concept that many candidates are currently missing."

Schwager advises college students to research a company before accepting their first job. However, she observes that this advice is increasingly relevant for senior-level positions as well.

Her hypothesis is that candidates who have come to her company through a third-party recruitment agency tend to struggle with the interview process. She believes that either they didn't read the prep or they weren't actively searching for the role. However, she advises candidates to do some research before the interview to show their engagement with the opportunity, otherwise it may be a waste of time.

She remarks that the candidate's immediate response indicates engagement and sets a positive tone for the conversation.

You may want to reach out to any mutual connections you have with your interviewer to obtain feedback on their work style as a colleague or manager.

One of her recent hires listened to podcast interviews featuring Schwager.

Some companies value direct communication with the top boss when expressing interest in a role. Schwager has found that her most enthusiastic hires have come from those who contacted her directly on social media.

To secure your dream job, enroll in CNBC's online course titled "How to Ace Your Job Interview." This course will teach you what hiring managers truly value, effective body language techniques, how to handle difficult interview questions, and the most appropriate way to discuss compensation.

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