School Days I went to Tsinghua University in China for my undergraduate degree, one of the top technical universities in the world. I spent two years in the Applied Math Department before switching to Computer Science. For graduate school, I went to Princeton University and earned my PhD in Computer Science.
Best Part Using my skills to build computer systems that serve people around the world. For example, in the early days of the World Wide Web (around 1995), there weren't enough cables to provide network bandwidth to ship information to people visiting websites. A technique called "caching" helped solve this. My team and I built caching servers that companies and network providers installed to make it easier for people to access websites.
Why Engineering? In middle school, I got into knitting. When a sweater that was just in my mind became a reality, I felt a huge sense of satisfaction. That's when I realized I loved building things. I also loved solving math problems. Algebra and calculus are elegant and beautiful to me. Figuring out the puzzle that leads to a proof gives me a sense of accomplishment. I combined these two loves and chose Computer Science.
Proud Moments Being elected to the National Academy of Engineering. I was shocked when it happened. I never felt I had done enough to merit this recognition, and I still feel humbled when I look at other NAE members.
What I Do I'm a computer scientist and programmer. I work with a team of engineers to build and improve computer systems used in YouTube and Google.
Challenges Graduate school was tough. In my third year, I couldn't find a thesis topic and felt very discouraged. I seriously considered quitting, so I wrote to my late father in Zhengzhou, China. He wrote back saying that even though a PhD might not help me get a better job than a Master's degree, the training in research would benefit me for life. Looking back, he was right. I was lucky to get his encouragement.
My Advice Don't believe the stereotype that coding is a loner's activity with a whiz kid typing alone in a basement. In reality, it's highly social. You read programs other people wrote and try to understand them. You make sure your programs are clear for others to understand. In engineering teams, teamwork is essential—if you review my code changes, I'll review yours. If I help you fix a bug at midnight, I'll text you on weekends when I need help too. Don't let the idea that "coding is anti-social" discourage you from pursuing computer science.