Kai received his B.E. degree in Electronic Engineering in 1993 from Shanghai Jiao Tong University, a top research university in China. He came to the U.S. in 1995 for graduate study, and obtained an M.S. and a Ph.D., both in Computer Engineering, from North Carolina State University. He has lived and worked in Silicon Valley since 2000. Kai's technical expertise is in telecommunications, and he has worked for major corporations such as Alcatel and Nokia. Kai later received both an M.A. in Economics and a J.D. from UC Berkeley; he is a licensed patent lawyer.

Kai has unabated passion in math throughout his life. Before he went to college at the age of 14, he placed first in a city-wide middle-school math competition in Wuhan, his hometown city that has a population of 11 million today. During middle school, Kai also won math-competition prizes at provincial and national levels. Kai still enjoys competition math today, after all those many years. Time has added just one dimension to his enthusiasm: now he loves working with today's young students, and is eager to pass his passion in math to them.

Kai has two sons, who attended Bullis Charter School, a small but top-rated public charter school in Los Altos, California. Kai coached Bullis students for Mathcounts from 2020 to 2022, during which period Bullis outshined five large and excellent public middle schools in the affluent towns of Palo Alto and Los Altos—with a disproportionally large number of Bullis students highly ranked in Mathcounts Chapter competitions. In 2022 a Bullis student with whom Kai had been closely working for two years excelled in California's super-competitive Mathcounts State and joined the highly coveted 4-member California National Team—a Bullis first. The student went on to succeed in Mathcounts National and was ultimately ranked No. 32 in the whole America.