[8] Medina began surfing at age four and at 11 won his first national championship, the Rip Curl Grom Search in the category Sub-12, held in Búzios, Rio de Janeiro.

[9] At 14 years old, Medina participated in the finals of the Paulista Championship, became the Paulista Junior Champion, and surfed at the World Qualifying Series (WQS) 6-star event Onbongo Pro Surfing 2008 in Ubatuba, where he managed to defeat his idol Adriano de Souza, aka Mineirinho.

Ten days later, Medina became the youngest male winner of an open-age pro competition by winning the Maresias Surf International in Brazil at age of 15.

[13] Medina signed an extension contract with Rip Curl just in the same week of his debut on the 2011 ASP World Championship Tour, by the age of 17, by the mid-season rotation.

[20][21] Medina also won the Billabong Pro Teahupoo, the seventh WCT event of the season in Tahiti, winning a highly competitive final with Kelly Slater.

After beating Mick Fanning and reaching the finals at the last WCT event of the season, the Billabong Pipe Masters in Hawaii, for the second straight year, Medina became the first Brazilian ever to win the Hawaiian Triple Crown of Surfing title.

On 14 May 2016, during the Oi Rio Pro, Medina made history and became the first surfer ever to land the move "Backflip" in competition.

As a result, Medina got a perfect 10 from all five judges, thus beating fellow countryman Alex Ribeiro in a 2nd round elimination heat.

[27] In the 2017 season, Medina made history as one of the two (Carissa Moore, in the women's division) first-ever surfers to win a competition in a man-made wave pool at Kelly Slater's Surf Ranch in Lemoore, California.

[36][37] In the 2019 season, after another sleepy start, Medina again claimed another win, his 13th CT event, in Jeffreys Bay, South Africa.

Medina competed in the Open Men's division and went on to finish the event with the bronze medal, behind fellow CT surfers Kolohe Andino (2nd) and countryman Ítalo Ferreira (1st).

[42] Medina was selected to represent his country in the 2020 Tokyo Olympics alongside 2019 WCT Champion Ítalo Ferreira.

He finished the Olympics in fourth place, narrowly losing to Australia's Owen Wright in the bronze medal match.

With 16 WSL Championship Tour (CT) event wins and 29 final appearances under his belt, Medina is one of the most experienced surfers when it comes to producing the best surfing under pressure.

[49][50] During the Olympics, Medina had the highest single-wave score of the tournament with a 9.9, and a picture of his subsequent landing appearing to float in mid-air became viral.

[51] The semifinal against Jack Robinson had Medina eliminated only surfing one wave, as the Tahitian sea calmed down and did not offer another opportunity for him to score.