The International Biology Olympiad 2019 took place at the University of Szeged, Szeged, Hungary from July 14-21. Bangladesh, along with about 80 other countries, participated in this mega event.
Bangladesh won three Bronze medals at IBO this year: Auddithio Nag, Madhav Vadhyan Sankaran and Rafsan Rahman Raayan. That is probably the fastest acquisition of hat-trick medals at any International Olympiad, at least for Bangladesh.