There are many details one could use to respond to this kind of question — for instance, you could highlight quantifiable achievements that match up to what’s requested of you. It’s a bit obvious but they would not have invited you to the interview as well as the other 15 people who have a similar skill set.
However, one of the things that a recruiter will be looking at (we believe the most important) is how genuine you are. We all have different upbringings, life and work experiences, and personalities. Those, combined, are difficult to mimic. Why did you show up for that interview in the first place?
- Do you need a job?
- Are you passionate about what this role entails?
- Do you like their culture and you think you’d fit right in?
- Are you excited at the growth opportunity in that position?
- Does the company have a great reputation as an employer?
These are all real & true reasons. Pick a few and be genuine about your answer.
Do it with a spin (if possible), again staying true to who you are: how does this job play out towards your dreams, your ambitions, and your career? Think of the long run or the well-known “what do I want to be when I grow up” — how this job is a stepping stone towards that (i.e. 20 years from now), and why that motivates you to master the skills required to succeed in this role. Most employers don’t have unrealistic expectations of keeping you around for the next 10 years or even 5 years.
If you don’t yet have a picture of what the long run looks like, don’t worry about it right then, and stick to the immediate things that really pushed you to apply for this job.
And finally: interviewers are human and will be prone to being subjective. You might have been bright and shiny at the interview, but if the interviewer had a bad day, that could have just been the only reason for rejection. Pick yourself up, and don’t give up on being who you are all the way through. Adjust the format but don’t compromise the substance.
To summarize: be genuine, paint a broader picture than that job, talk about what drives you to succeed, be genuine about it.