7 Things You Can do After a Really Bad Interview.

You can’t rewind and redo the interview—nor can you change the employer’s decision to offer you a job. But there are a few things you can do after a bad job interview to help you avoid such mistakes in the future, to mend the employers impression of you, and, if you’re really lucky, to help them understand and overlook your mistakes.

Reflect on the experience.
“I talk to many students who believe they have bombed the interview,” Brooks says. “The first thing I do is ask them what went well.  It’s important to discover what went well first so that you’re able to look at the negative aspects with a less defeated attitude.  I then ask what one thing they would change.” If you have a bad feeling about the way things panned out, identify exactly what went wrong.

Learn from it.
Make a list of the mistakes you made during the interview, learn from them, and do better next time, Stewart says.
“The best thing to do with a bad interview is learn from it,” Brooks adds. Don’t wallow in self-pity or allow the bad interview to be an excuse for not following-up or not interviewing for a while.  Instead, ask yourself what you would do differently to prepare next time; figure out what information you should have had that you didn’t; and think about how you would handle a difficult question next time.

Learn to forgive yourself.
“This will help you to play better in the game in the future,” Stewart says.
Nothing good ever comes from beating yourself up. It’s natural to feel uneasy for a little while—but don’t let the feeling linger and don’t let it discourage you from reaching out to the employer to make things better. Accept your mistakes and move forward.

Explain what went wrong in a follow-up thank you note.
Don’t make excuses, but do acknowledge your blunders. “For example, if the candidate believes their responses to questions were off target, he or she can send a well crafted follow-up letter to the interviewer admitting a misunderstanding of the questions. This might make a difference,” Canchola says.
However, make sure you only draw attention to the mistakes you’re absolutely certain the employer caught, or you’ll bring light to an issue that the interviewer might have otherwise missed.

Use the thank you note to add anything you might have forgotten to mention.
“Maybe the candidate forgot to tell the employer a significant part of their work experience or education that would be relevant,” Brooks says. “Or maybe they forgot to mention a connection they have in the organisation.  This sort of thing can be remedied with a quick thank you e-mail to the person who interviewed you.” The thank you note is also a great place to remind the employer of your strong points or what went well during the interview.

Inform the employer of any outside distractions.
If your interview fell flat because you were distracted by a serious life event—it’s okay to call or e-mail the employer afterward to explain, Canchola says. They may take this into consideration when they assess the interview.

Never apologize for a bad interview—but do say sorry for specific slip-ups.
Remember, you don’t know what the employer is thinking, and maybe it wasn’t as bad as you think, Brooks says. If you did something that requires an apology, it’s a judgment call. “If you already apologized in person–say you accidentally spilled water on the interviewer–there’s no point in repeating that apology.”  You don’t want to keep reminding the interviewer of what went wrong.
However, if you realize you accidentally called the interviewer by the wrong name, for instance, but didn’t realize it until later that you called her Mary instead of Marie, that might warrant an apology in your e-mail. “Mention that you were mortified after the interview when you realized that you called them by the wrong name,” Brooks says. “You can use an excuse, like ‘my best friend is named Mary’ or you can just say, ‘sorry, I’m usually much better with details than that.’”