After majoring in theater studies at Seoul Institute of the Arts, he joined the writing team for the SBS variety show Good Friends in the mid 1990s.

He created his own portion Hollywood Message, which he wrote and edited by himself, where he would take famous scenes from some of the most popular Hollywood films showing in theaters, and make parodies, add silly popups, mix scenes from different films together to form a bizarre, unique collage of images.

[2] In January 1995, Jang entered newspaper daily The Chosun Ilbo's annual literary contest with Cheonho-dong Crossroad, his first full-fledged script.

Using three characters which would feature in most of his theater plays and early films (Hwa-yi, Dal-soo and Deok-bae), his new and creative brand of storytelling won over the judges, who awarded him the top prize.

[2] It would take another few years before Jang could start working full-time in Chungmuro, but during that time, he built a reputation as one of the most brilliant theater directors in the country, with unique scripts and characters who came across as real even in the most surreal of situations.

Jang decided to shop around his script, which led to his debut feature 1998 comedy The Happenings (though only half of what he shot ended up in the final cut).

The fantasy dramedy was the debut feature of Park Kwang-hyun, one of several of Jang's colleagues from his theater days who joined Film It Suda.

He directed his fellow Seoul Institute of the Arts alumni in a staging of Arthur Miller's Death of a Salesman.

His next films, 2010 ensemble comedy The Quiz Show Scandal[26][27] and 2011 melodrama Romantic Heaven,[28][29][30] though well-reviewed, were less successful at the box office.

[37][38] Considered one of the most distinctive voices to emerge from the 1990s Korean cinema renaissance, Jang's unique filmmaking style mixes unconventional storylines, quirky characters, dry and subversive humor, comic twists, sharp puns, stagy presentation, a keen observation of society, and humanism.