Barbora Malíková gained her first international experience at the U18 World Championships 2017 in Nairobi , where she won the gold medal in 52.74 seconds. She then won the silver medal at the European Youth Olympic Festival (EYOF) in Győr and was eliminated in the first round with the Czech 4 x 100 meter relay, but won the sprint relay (1000 meters) in 2: 13.64 minutes the bronze medal. The following year, she won the U18 European Championships there in 52.66 s over 400 meters and also won the silver medal behind the team from Italy with the sprint relay (1000 meters). In mid-October she also won the Youth Olympic Games in Buenos Aires in 54.68 s. In 2019 she won the bronze medal at the U20 European Championships in Borås, Sweden, in 52.37 seconds, setting a new U20 national record.
In 2017 and 2020 Malíková became Czech champion in the 400-meter run.