I’ve been interviewing developers for seven years. I’ve seen some great candidates, and I’ve seen some horrible ones. Here are some of the worst mistakes I’ve seen — hopefully you can avoid them.

Mention how overqualified you are for the position.

I work in front-end development. It’s amazing how many designers and back-end developers we get in for interviews who think that front-end development is just something that people do on the side while focusing on real work like design and back-end development. I’ve had a few interviewees with multidisciplinary work experience mention that they’re overqualified for the position, but they still wanted to be considered for it. Want to guess how they turned out? In every case, they bombed the interview.

Imagine walking into a car dealership and asking to see their selection of trucks. The salesman immediately takes you over to a sports car and starts expounding on how great it is, even going as far as saying that the sports car is overqualified to be your truck because it’s a sports car. That’s how you sound when you say that your irrelevant experience is more important than what we asked for.

Doing a different job does not make you more qualified — it makes you less experienced. That’s not to say that there’s no carry-over between disciplines or that experience in another area has no value. But if we’re looking for something specific and you haven’t been doing it, don’t ever assume that what you’ve been doing is more advanced or important. If you’re truly overqualified, you won’t have to state it; if we’re worried about it, we’ll mention it. But if you say you’re overqualified and you’re not, you’ve shown you don’t respect or want to learn the new job, and you probably just lost your chance at it.

Show us how unenthused you are about the position.

I had a guy in for an interview right after a major election. In the interview, I very quickly found out that he had been trying to get elected as a United States senator. I also very quickly found out that development was the guy’s back-up plan — and one that he was not excited about using. The guy was glaring at me through the whole interview, and was very clearly humiliated to have lowered himself to be interviewed by me. He did not get the job.

In another interview, I had a guy who actually insulted the entire front-end field, saying he was only applying for the job in hopes of transferring to a “real” developer position later on. Yeah, he also said he was overqualified for the position because he knew a little PHP. And he also bombed the technical portion of the interview. But he’d lost the job before then.

If we don’t get the sense in the interview that you’re going to work hard at the job, you won’t get another chance to prove it to us. That’s a decision you need to make before you come in for the interview, and something you’ll need to prove to us, because most other applicants will be working hard to do just that.

I get it — sometimes you have to take a job you’re not the most excited about. But if you don’t give every job your all, you’ll have wasted any time you spend in them. Let’s say you take a job you’re not excited about, but you put in the effort and the hours and really excel at it. Worst case, after a year, you’ll have a list of great achievements and references for your career; best case, you find yourself promoted into a better position or put on better projects that will make the job a good one.

Babble endlessly.

I was in an interview and asked a particularly chatty candidate about his greatest accomplishments. Fifteen minutes later, he was talking at length about his co-workers’ coffee preferences and had yet to list an accomplishment. The team lead in the interview with me made up his mind and quietly got on Facebook, leaving me alone in an extremely awkward one-sided conversation. I had to cut half of the planned questions because he took so long answering them that we ran out of time — and he still didn’t answer most of the ones that were actually asked. Overall, a total disaster of an interview.

Now before you start thinking that I’m being petty here, we contacted people he used to work with and got the feedback that he was very nice and knowledgeable, but took forever to complete a task and was unproductive in meetings. I know correlation is not causation, but I had a pretty good feeling on that one. Screening for brevity is a very legitimate thing to do because it’s an accurate predictor of how efficient a worker you will be.

There was another interview I did earlier on in my management career. The guy’s cover letter was three pages long and his resume five pages long, despite only being in the industry for four years. I decided to give the guy a chance anyway. About three minutes into the interview, I discovered that the resume and cover letter were indeed accurate predictors of how chatty he was. After 20 minutes of senseless rambling and pontification, the director in the interview with me excused herself, once again leaving me alone with the interviewee. (Why does this keep happening to me?)

Please don’t hear that we want terse one-word responses to all questions. We want to hear you talk — that’s the reason we’re conducting an interview rather than just giving you a test. But we want to hear you talk with relevance to the position. We want to hear you answer our questions just as thoughtfully as we selected the questions. And we want to know that you’ll be able to focus on your work and get it done quickly. Succinctly making your point goes a long way in making your answers more impressive.

Badmouth the people you used to work with.

(The names in the below story have been changed because I don’t want to get sued.)

“Well, Chris, you work at X Company?” I asked the applicant in front of me. “We have an employee who used to work there.”

“It’s not Bob, is it?” applicant Chris asked.

“Why do you ask?” I inquired.

Chris launched into an angry diatribe on how Bob didn’t work unpaid overtime on his last day at the company to finish up a project with a ridiculous deadline. Chris hated Bob. Just then, the door opened.

“Chris, this is my senior developer, Bob, who will be joining us for the interview.”

That actually happened. Chris did not get the job. Bob and I still laugh about that one.

It can be tempting to speak ill of your current or past companies — after all, you’re not leaving them because things are just too good there. This is a bad idea for a number of reasons.

First, as illustrated above, the development communities in cities are often smaller and more closely-knit than we think. After eleven years working in development in Kansas City, I know people at all of the major shops and have worked with a lot of them.

Second, your reaction to your current or past workplace is pretty indicative of how you’re going to react to unwanted change when we hire you. The fact is, there will be things you don’t like no matter how great the job is, and if we sense that you’re a chronic complainer, that can impact employee morale or even client relations.

You’re welcome to mention the negative things about your current or past employer, but do so gracefully and diplomatically. In fact, this can be even more beneficial than not mentioning them at all, as it shows you know how to restrain yourself and respect professional boundaries. Just don’t use an interview as an opportunity to vent your frustrations — that definitely will not help you.

Don’t proofread your anything.

No joke, I once got a resume where the guy misspelled PHP. If you can’t even spell the technologies you’re allegedly an expert in, that doesn’t speak well to your expertise.

My wife works in HR, so she reviews resumes too. She once saw one where a candidate mentioned her “critial eye for detail.”

I don’t think I need to elaborate too much on this one. If you’re not gifted in proofreading, get a friend to do it. But one way or another, you need to do it.

Insult people with real conditions.

I was interviewing a guy (who, by his own admission, was not great with people) and I asked him to tell me about a project that did not go as planned. His reply involved this:

“Oh man, the code on this site was so bad, the developers had to be bipolar or something.”

Hmm, so people with bipolar disorder can’t write good code. I don’t remember seeing that on the list of symptoms. I’m quite familiar with the list of symptoms because I happen to have bipolar disorder myself. And I’m a bit mystified by his statement, because I wasn’t interviewing him as a team lead or manager — I was interviewing him as the technical architect. It was literally my job to not write bad code.

But let’s humor him. Let’s apply this thinking to some other medical conditions:

“Oh man, the project manager ran that project so loose, he had to have irritable bowel syndrome or something.”

“Oh man, the back-end security on that site was hindering the user so much, the developer had to have lupus or something.”

“Oh man, the client’s appetite for leads was so low, she had to have had stage IV pancreatic cancer or something.”

Yeah, still not funny.

It’s 2017. I can’t believe I have to explain this. Medical conditions (and other conditions, like trauma, family situations, or even gender identity) are very real, and are sometimes very hard to deal with. When we interview you, we look out not only for ourselves, but for everyone on our teams, and for everything they could possibly have to deal with in the future. Your bipolar jokes could trigger someone on our teams who just had a bipolar relative commit suicide. There is no situation in which joking about someone else’s condition will help you get a job. Don’t do it.

And if you’re wondering, he did not get the job.

Don’t restrain yourself on social media.

I had an applicant once — a referral from a coworker. The first thing I do when I get a resume is Google the applicant and see what I can find. Portfolio? Great, I’ll check it out. Social media? You’d better believe I’m going to check that out. In this case, the guy’s Twitter handle was — I kid you not — something along the lines of Lord Dickhead. I read a few of his Tweets, and the account was appropriately named. To make matters worse, most of the foul-mouthed Tweets were directed at his current employer. He didn’t get the job. He didn’t even get an interview.

Please remember, anything you put on the Internet is fair game for me to read and use in my assessment of you as a candidate. I’m trying to get a feel for who you are and what kind of teammate you’ll be, and I know that I may get a skewed view of you based on what you present in the interview. So, once again, you’d better believe I would jump at a chance to take a look at an unfiltered stream from you.

Now, I’ve heard horror stories of people who lost their jobs because they were holding a drink in one Facebook photo. We’re not that uptight. I fully realize that people have a right to speak freely on the Internet in a non-professional setting, and I probably won’t approve of everything they do (just like they probably wouldn’t approve of everything I do online). But if the severity or the frequency of the faux-pas posts gives me concern for how they’ll handle themselves in the workplace or how they’ll portray our company to the public, yes, I will take notice, and it could impact your chance of getting the job.

Just blocking everyone on all social media channels isn’t necessarily the best plan of action either. Yes, it hides all your embarrassing posts, but it also does nothing to help you. A good social media presence with thoughtful and relevant posts can greatly increase our interest in you as a candidate. And remember that just because your social media profiles are private does not necessarily mean that employers will never see them. The best course of action is to avoid putting damning information about yourself online, no matter the channel.