[4] During the 2015 season, he showed outstanding performances with 15 goals in the K League 1, and made his debut in the South Korean national team.

[9][10][11] On 15 July 2019, Hwang moved to Ligue 1 club Bordeaux, signing a four-year deal worth €1.8 million per year.

[12] He originally played as a striker for the South Korean national team and Gamba Osaka, but the Bordeaux manager Paulo Sousa usually used him as a winger.

[20] Although he didn't score many goals, he played a key role in FC Seoul's attack, helping the team retain possession and apply pressure on opponents.

He scored a hat-trick in the first group stage match against Bahrain on 15 August [29] and another in the quarter-finals against Uzbekistan, leading South Korea to a 4–3 victory.

[32] On 25 June 2023, an unidentified user on the social networking service Instagram posted explicit clips of a sex video, allegedly showing Hwang and a woman who did not know she was being filmed.

[34] She also claimed that videos on his mobile phone with these women may have been taken without consent or by hidden cameras; she posted private conversations and recordings on the social media platform.

The sister-in-law, who has only been publicly identified by her surname "Lee", was charged with violating South Korean laws relating to sex crimes and committing blackmail.

She originally denied the allegations, but later confessed that she leaked the videos as an act of revenge as she felt Hwang had "[been] ungrateful" towards her and her husband for their support of his career.

[36][37] Concurrently, a second police investigation was launched into allegations that the sex footage on Hwang's mobile phone had been filmed without the knowledge or consent of the women involved.

[39] On 11 July 2024, Seoul Central District Prosecutors’ Office informed Hwang that he was to be indicted on two charges related to alleged breaches of South Korea’s Act on Special Cases Concerning the Punishment of Sexual Crimes.