If you can't discuss a failure or mistake, the recruiter might conclude that you don't possess the depth of experience necessary to do the job. The recruiter is not looking for perfection. He or she is trying better to understand your level of responsibility, your decision-making process, and your ability to recover from a mistake, as well as what you learned from the experience and if you can take responsibility for your mistakes.

Respond that you'd like to think that you have learned something valuable from every mistake you have made. Then have a brief story ready with a specific illustration.

It should conclude on a positive note, with a concrete statement about what you learned and how it benefited the company.