How Did China Develop the J-35 Stealth Fighter So Fast?                                                       

One suspicion about the sudden advance in China’s aerospace program has been a predictable one: China cheated.

"...One suspicion about the sudden advance in China’s aerospace program has been a predictable one: China cheated. One retired U.S. Navy captain described Beijing as having achieved in a decade a level of technical prowess it took the Navy a century to achieve and cited the country’s ability to use both open-source and stolen data to improve its programs....

....China has certainly made domestic advances in aerospace design, too. Between this and illicitly acquired data, however, there is a (link:) striking and probably non-coincidental similarity between the most recent iteration of the J-35 jet and America’s F-35 jet. It remains to be seen, however, if the J-35 jet can perform at the level of its American counterpart. "

https://nationalinterest.org/blog/buzz/how-did-china-develop-j-35-stealth-fighter-so-fast-190080