Actually sad to say, at least in the USA, it is not generally illegal to discriminate against someone because they are too young (any age under 40): https://www

Actually sad to say, at least in the USA, it is not generally illegal to discriminate against someone because they are too young (any age under 40): https://www.eeoc.gov/laws/types/age.cfm https://www.eeoc.gov/laws/types/age.cfm . I know from other comments that you were being interviewed in Germany, so YMMV. Your best bet in a situation is two possibilities. 1) You recognize such a question means the firm is not a good fit for you. Then it doesn't really matter what you say. 2) You're displeased but still are willing to put up with a company that dings you for that. In that case, I would open by talking about how much experience you have and how mature you are. Focus on that instead of the age.