He won the Korean Tour Order of Merit in 2024, and was a gold medalist in the team event at the 2022 Asian Games.

Jang had a successful amateur career, winning several ranking tournaments, including the 2022 World University Golf Championship.

He was part of the gold medal winning South Korean team in the 2022 Asian Games (held in 2023), playing alongside Kim Si-woo, Im Sung-jae and Cho Woo-young.

In 2024, he successfully defended the KPGA Gunsan CC Open,[4] as well as winning the Baeksang Holdings-Asiad CC Busan Open[5] and had several runner-up finishes, on his way to winning the 2024 Order of Merit and Player of the Year award.

[6] In December 2024, he dropped out of the final qualifying stage for the PGA Tour in order to join LIV Golf as a member of the Iron Heads GC alongside Kevin Na.