HO CHI MINH CITY -- It is a hazy afternoon in Ho Chi Minh City, and Vuong Quang Khai has just pulled up in a compact SUV to introduce Nikkei Asia to Kiki, his company's artificial-intelligent voice assistant.

An employee walks past a sign for Zalo, the division of tech unicorn VNG that made Vietnam one of the few countries in the world with its own chat app more popular than foreign rivals'. © Lien Hoang
VNG built the country's answer to WeChat; now it is aiming even higher