Change is prevalent in the workplace today, and the interviewer wants to know that you can embrace change rather than become thrown off by it.
Think of a story-based example that you can share with the interviewer where you faced change but the result was positive. Perhaps your job duties shift, or there is a significant revision to store policy. Maybe you will have to welcome a new manager you're not particularly fond of, or your company is acquired by a competitor. These situations make great examples to draw on to showcase your ability to be adaptive in the workplace.
If you do not have previous work experience to draw from, think of an example from school, volunteer work, or a sport you are involved in. Highlight the fact that you are able to adapt quickly to changes while still being able to meet the primary goals and tasks that are in front of you. Describe skills that you have that allow you to adapt to change, whether you are good at keeping calm under stressful situations, you are a quick learner, or you have excellent problem-solving skills. The interviewer should be confident that you are open to challenges or even thrive off of them.
