Kijoo Chang, chief financial officer of Kakao Pay Corp., South Korea’s largest mobile payments app, discusses the company’s strategy and outlook. Kakao Pay more than doubled in its debut in Seoul on Wednesday, following a rocky path to public markets that was marked by heightened regulatory scrutiny. The startup, backed by Jack Ma’s Ant Group Co., raised 1.53 trillion won ($1.3 billion), giving the online payments service a market capitalization of more than 11.7 trillion won before the start of trading.