This is one of the most common questions that are asked during interviews. Avoid answering with a character trait as those will be more difficult to bring to a team. When answering this question the most important thing to remember is, to be honest. You need to perform an honest assessment of your skills relative to the requirements of the job and identify some legitimate areas for improvement. Tell the interviewer about a functional weaknesses or skill deficiencies as can be addressed through learning and development.