Apple is very proud of our products and the people who develop them. In your opinion, what distinguishes a great software engineer from an average one?
When an interviewer asks this type of question, they seek to understand what your perception of excellence in this role is. When answering the question, you should align your response with the job requirements, as defined in the job posting. You can also incorporate your past performance to demonstrate that you are aware of what excellence is and strive to achieve it.
"I believe that the trait which distinguishes a great software engineer from an average one is being able to balance excellence and performance. While I strive to write perfect code, I recognize that the project has a deadline and needs to be accomplished on time and under budget. If I have to compromise the quality of my code, it is done in such a way that it will not impact the final performance of the product."