Attributes contributing to a successful UPSC interview performance include strong communication skills, confidence, and the ability to think critically under pressure. Candidates should articulate their thoughts clearly and concisely, demonstrating familiarity with the subjects they're questioned on. A composed demeanor and positive body language can significantly impact the impression made on the interview panel. Additionally, showing genuine enthusiasm for public service can resonate well with evaluators. Lastly, being prepared for questions ranging from personal experiences to current affairs indicates thorough preparation, enhancing overall interview performance.