Critical skills needed for performing well at the UPSC interview stage include communication, confidence, and critical thinking. Candidates must articulate their thoughts clearly and concisely while displaying poise under pressure. Active listening is equally important, as it allows for thoughtful engagement with the panel. Demonstrating a thorough knowledge of current affairs and understanding of civic issues is crucial. Additionally, having well-structured arguments and the ability to remain calm while addressing challenging questions can greatly influence the interviewer's impression. Building a rapport with the panel can also enhance the overall interview experience.