At only age 16, Miracle03(Mingyang Deng) reached Legendary Grandmaster on Codeforces Round #564 (Div. 1). What's more, he won the first place in the Chinese team selection for IMO2019 and will be a participant of IMO2019.
It's a pity that IMO2019 and NOI2019 (a necessary step in Chinese team selection for IOI) are conflicted in time, and he will probably not be able to participate in IOI2020. However, he's in grade 10 now, so he still has the chance to participate in IOI2021.