This is a general question the interviewer will ask early in the interview to begin the conversation, learn more about your background, and collect information they can use throughout the interview. You should anticipate this question and prepare for it by reviewing the job posting. This will indicate what the organization thinks the roles and responsibilities of a systems engineer are and their expectations for candidates applying to this position. You should also review your resume, so you're familiar with the interviewer's information to evaluate your qualifications.