So what I'm hearing is that the Chinese are better at calculus than the Americans, sounds about right.
Although the article doesn't get into any detail, it sounds like what they're doing is applying similar optimization techniques to those that have enabled the past 15 years of AI/ML development in order to optimize their aircraft design. It's not surprising that China was able to do that; there's been an enormous amount of work into developing math, software, and hardware for that stuff. But what's more surprising is that the US hasn't implemented it already. I guess the X-47B program was halted right as the ML/deep learning explosion started so these teqniques weren't really widespread yet. But I find it hard to believe that the US hasn't done it already.