Pony Ma is well known as the co-founder and chief executive of Chinese tech giant Tencent, which operates the ubiquitous app WeChat. The bookish Mr. Ma, whose passion outside of work is astronomy, has long been the public face of Tencent.

But the key executive in Tencent’s daily operations is as much President Martin Lau as Mr. Ma. All of the top Tencent executives report to Mr. Lau, a former Goldman Sachs banker who joined the company in 2005, except Daniel Xu, one of Tencent’s co-founders whose current title is chief information officer, The Information has learned. Even some of Tencent’s current and former managers who spoke with The Information weren’t aware of Mr. Lau’s breadth of direct reports, due to Tencent’s policy of keeping its organizational structure confidential.