Landing a job interview is a crucial step on the road to getting hired. But if you're not careful during that initial meeting, you could ruin your chances of scoring the role you've been vying for.

Now, there are plenty of mistakes you might make that could cause you to botch an interview. You might mistakenly call your interviewer by the wrong name (it's been known to happen before) or fumble through a tricky question. But if there's one way to really wreck your chances of getting a follow-up meeting or the job you're applying to itself, it's bashing a previous employer, according to job site Glassdoor. In fact, CareerBuilder reports that 48% of companies have passed over a candidate for doing just that.

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Of course, if you had a bad experience at your last job and still aren't over it, avoiding this error might prove challenging. Similarly, during an interview, you're likely to be asked why you left your former employer, thus opening up that can of worms. So here's how to tackle that inquiry without coming across as unprofessional -- and turning off your interviewer in an instant.

1. Leave the baggage at home

Maybe your last boss was completely awful, or your company's management team refused to give you a promotion despite your stellar performance. No matter the case, aim to let go of that anger -- at least temporarily -- before you sit down to interview for a new position. Chant a little mantra in your head on the way there if need be, or go to the gym and hit a punching bag afterward to get your aggression out. Just don't drag that baggage into an interview because once you let a few unkind words slip, a tirade might ensue.

2. Focus on the job, not the company or people

Generally, there's a reason why people leave jobs, so there's nothing wrong with expressing dissatisfaction with your former role. But if you want to come off as more professional and less petty, focus on the elements of the job itself that caused you to leave, rather than the company or people. For example, if your boss and management team were incompetent, and you spent your days doing mindless tasks as a result, don't say that. Instead, explain that you felt your skills were being underutilized at your last role, and that you're looking for an opportunity to make more of an impact elsewhere. That's a perfectly legitimate reason for leaving a job -- and one that won't make you look like you're holding a grudge.

3. Sprinkle some positives in with the negative

Clearly, your last job was far from perfect -- otherwise you wouldn't have left it. But chances are, there were at least one or two good things about it, even if those factors were largely overshadowed by the negatives. When faced with the topic during an interview, aim to throw in at least a few kind words about your previous company in the context of your departure.

You might try something like this: "While the company was making great strides toward developing new technology, I felt I was pigeonholed into a role that didn't allow me to contribute as much as I would've liked." Or you might say something along these lines: "Though I benefited from a supportive manager and great colleagues, I wasn't learning as much on the job as I wanted to." Having a few good things to say about your last employer will not only speak to your professionalism but also give the impression that you're a positive person in general.

Trashing a former employer is a good way to ensure that you won't make it past your first round of interviews, so resist the urge to do so at all costs. Remember, a job interview is never the right forum to vent about anything, let alone your previous company, so keep yourself in check if you want a shot at landing that job.

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