throwaway1p3a

A few questions: do you repeat any interview questions across candidates? Do you work for a company that sponsors H1Bs? Does your company have some "prestige" (either a highly visible startup or one of Facebook/Google/Microsoft/Apple/etc)? If so, then your questions are almost certainly available online and talked about in detail within the Chinese community.

I would like to point you to (and encourage a search of your questions or your company): https://www.1point3acres.com/bbs/ . This is probably the largest board out there that shares interview questions (and answers!), techniques, approaches, etc... including leaks of questions, "help" from insiders at large companies, and more. If you seem to suspect that there is some sort of nation-based component to your Chinese interviewees doing quite well, I suspect you may find your study is poisoned and I recommend a redo. As an American, I have not found something similar to 1p3a in terms of the wealth of information available for getting recruited at large companies.

1p3a isn't the only one out there either. There are many more. This is just the one I've been able to hear coworkers and students when I was in undergrad talk about a lot.