John Byun is Chief Information Security Officer (CISO) at Sephora USA, where he leads enterprise information security strategy, cyber risk management, and resilience across the company’s global digital and retail platforms. Based in San Francisco, John partners closely with executive leadership and technology teams to enable secure innovation while protecting customer data and business operations. Known for his pragmatic, business‑aligned approach to security leadership, he brings deep experience in building scalable security programs for modern, technology‑driven organizations.