Over the last decade, I’ve founded multiple companies, interviewed over 500 candidates, and hired more than 100 people.
As the CEO of two companies, I’ve made every hiring mistake you can imagine — and learned how costly they are.
The truth is, many bad hires look great on paper. But in the interview, there are three subtle behaviors that almost always predict trouble. Job seekers should know them, because to hiring managers, they’re giant red flags.
1. Show up late, and it signals a lack of preparation
If someone shows up even a minute late to an interview, it raises questions right away. Sure, emergencies happen. But most of the time, it signals poor planning.
When someone doesn’t protect time for the interview, I have to assume they won’t protect time for clients, deadlines, or teammates once they’re in the role. In fast-moving agency environments, that can create real problems.
Do this instead
Aim to be early, even if it’s a virtual interview. Log on 10 minutes ahead of time and test your tech.If something unavoidable does come up, communicate right away. A quick message goes a long way.Treat the interview with the same respect you’d give a client meeting.
2. Polished words without substance don’t land
Some candidates are great talkers. They sound smooth, confident, and quick on their feet. But when you listen closely, their answers aren’t rooted in personal experience.
I’ve had interviews where a candidate gave me a full paragraph that sounded smart, but when I replayed it in my head, I realized there was no real example, metric, or detail.
In the age of AI, leaders want proof that you’ve faced challenges, solved problems, and delivered results — not just that you can sound good talking about them.
Do this instead
Instead of simply claiming strengths, the best candidates show them.
Replace buzzwords with proof. Instead of “I’m collaborative,” tell a story about how collaboration helped you save a project.Use the STAR method (Situation, Task, Action, Result) to structure answers.Prepare a few stories that highlight how you’ve put key skills into practice and how you’ve handled real challenges.
3. Energy in the interview (or lack of it) says a lot
For me, energy is one of the most telling signals. The interview is your best-case performance — if you show up flat, it won’t get better once you’re actually on the job.
That’s especially important in client-facing or high-pressure roles. I’ve seen how much energy matters. A candidate who brings enthusiasm, curiosity, and presence to the conversation is far more likely to thrive than one who seems muted or disengaged.
Do this instead
Acknowledge nerves but channel them into enthusiasm.Show engagement with tone, posture, and thoughtful questions.Let the interviewer see your real personality. Don’t fake this by pretending to be someone you’re not. Most people can see right through it.
One good rule of thumb for any job interview is to bring the best version of yourself into the room. Remember that you’re not just being evaluated on your skills, you’re showing your prospective boss and team how you’ll show up day after day if they decide to hire you. So help them imagine what a great choice you’d be.
Eli Rubel is a life-long entrepreneur and currently serves as the CEO of Profit Labs, a strategic finance, bookkeeping, and accounting firm for agencies, and SurveyGate, a SaaS tool that helps business owners automatically capture objective client feedback. He also owns a small portfolio of services businesses, which includes NoBoringDesign, a design and creative agency for technology companies, and Matter Made, a B2B performance marketing agency for technology companies.
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