Job interviewers share 17 mistakes that instantly tanked a candidate’s chances

From the interviewer’s seat, job interviews are more than just a conversation—they’re a window into how a candidate thinks, communicates, and reacts under pressure. But sometimes, subtle red flags or glaring missteps can reveal that a person might not be the right fit.

Recently, a fascinating question popped up social media: “People who give job interviews, what are some subtle red flags that say, ‘this person won’t be a good hire’?” The answers poured in, revealing a mix of subtle missteps and jaw-dropping moments that interviewers couldn’t ignore.

Here are 17 of the most telling examples from the Reddit thread, ranging from everyday mistakes to non-sensical self-sabatoge:

1. Showing up late and disheveled—but with a plot twist

"I once had a guy show up (late) with blood all over his face and clothes looking really disheveled. Typically, I don’t waste my time with people who can’t even make it to their interview on time. But this guy said that he was in a car accident on his way to the interview and got there as soon as he could.

After the interview, he asked if there was any way he could get a ride back to where his car was. Believing his story, I offered him the ride. This man’s car was nearly FIVE MILES AWAY, legitimately crashed, and it turns out someone had broken into his car and stolen his child’s car seat and his stereo system during the couple hours he was gone.

I hired him. He turned out to be really difficult to work with, but the guy was a programming genius." — u/van_ebasion

2. Smoking during an interview

"Was giving an interview, maybe 20 minutes long. The lady being interviewed asked if she could go outside and smoke a cigarette." — u/Fury161Houston

3. Trash-talking previous employers

"I once interviewed a woman who took the interview as an opportunity to vent about how terrible and unfair her previous job was." — u/PennilessPirate

4. Bringing parents to the interview

"Showing up to the interview with a parent in tow. I've had this happen twice and both times I refused to go through with the interview. Grow up, people! You don't need mommy or daddy with you at your professional job interview!" — u/Linux4ever_Leo

5. Over-reliance on AI for answers

"Had one person who was literally forwarding our questions into ChatGPT and then reciting rambling answers that provided definitions of keywords in our questions rather than actually answering the question." — u/Fast_Moon

6. Not asking any questions

"In IT, not asking any questions. An interview should go both ways. You should ask me about my company and team. Not only does it show interest, but it gives you information to make a decision." — u/vellian

7. Poor attention to detail

"I had someone send their resume through an email chain for existing customers. The kicker was the first line of their letter was 'they keep close attention to detail.'" — u/houseonpost

8. Answering a “weakness” question with arrogance

"‘One of my weaknesses is I work too hard.’" — u/ocdano714

9. Lying on a resume

"So many people lie or exaggerate their experience on their resume. Then, when interviewed, they can't answer basic questions about key tasks in the role." — u/maeasm3

10. Showing up in pajamas

"I had 3 different people show up for interviews wearing their pajamas. One of them even had a robe, a do-rag, and a beat-up stuffed animal, and kept sucking on a pacifier." — u/IcyAd7982

11. Openly expressing disinterest in the job

"I asked someone in an interview why they wanted the job, and they said it was just to fill in until they could find something better." — u/Eiteba

12. Negative body language

"Men who avoid eye contact or direct communication with women. Lots of men in my field (STEM) don’t want to interact with women and will answer questions from female interviewers as though the man sitting next to her had asked it. I refuse to hire anyone with that BS attitude." — u/2sad4snacks

13. Failing to follow simple instructions

"When I call in a group to interview, I give simple instructions: bring your ID, a pen, and a piece of paper. 90% of the people who show up fail to bring those three things and immediately get rejected. Can't follow simple instructions? Why would I trust you with equipment worth thousands of dollars?" — u/StruggleBusDriver83

14. Overconfidence with no substance

"I interview PhDs often, and they split into two categories: 'I've done my homework and I'm ready to answer any question' (good) and 'I am better than this job and you will give it to me, but I'll join the charade' (bad)." — u/Klumber

15. Talking more than listening

"When interviewing people, I always try to find a way to subtly disagree or challenge one of their positions. Some people confidently back up their claims (green flag), but others get defensive or territorial when challenged (red flag)." — u/BckCntry94

16. Being unable to admit gaps in knowledge

"I always keep asking questions until I find something they don’t know. If they don’t say ‘I don’t know’ at that point, huge red flag. Nobody knows everything. Being able to recognize when you’ve encountered a subject outside of your knowledge is essential." — u/Hot-Incident-5460

17. Complaining about the hiring process

"I once interviewed someone who said, ‘I don’t want to waste your time.’ I immediately thought, ‘Why are you wasting mine then?’" — u/houseonpost

Interviewing for a job is never fun, but fortunately there are always some candidates you'll always look better than.