As of January 2020, they had 2,532 full-time employees. Of those, 1,396 were in the US and 1,136 were in international locations. Within the 1,136 is "more than 700" employees in R&D in China.[1]
A LinkedIn search for "engineer" working for "Zoom Video Communications" in location "United States" shows up 558 results.[2]
Their entire management team is in the US, and of their 17 data centres, only 1 is in China.[3][4]