[6] Hwang lived in Davao City, Philippines, during his high school and college years, going by the English name Ryan Leon.

[18] He played Goo Ja-sung, a school bully and the counterpart character of Stan, who was portrayed by Hunter Parrish in the original film.

Hwang participed in the 2020 drama tvN romantic-comedy series True Beauty, based on the on-going Webtoon of the same name.

On April 23, 2021, Keyeast announced that Hwang had signed a contract with Japan's agency Stream Media Corporation.

[23] Later, Hwang confirmed to star in the SBS mystery legal drama Why Her which premiered in June 2022 marking his first lead role on a terrestrial TV station.

He has training in various martial arts such as Taekwondo (where he is a 3rd dan black belt), Hapkido and Kendo (or Kumdo as it is known in South Korea).