[citation needed] He began to gain attention in the TV industry when he wrote the historical epic Dae Jo-yeong (2006-2007), which starred Choi Soo-jong as the titular founder of the state of Balhae.
After Dae Jo-yeong, he and wife Jung Kyung-soon became writing partners again, and they would become best known for their collaborations with director Yoo In-shik—the hit dramas Giant and History of a Salaryman.
Giant (2010), starring Lee Beom-soo, Park Jin-hee, Joo Sang-wook, Hwang Jung-eum, Park Sang-min and Jeong Bo-seok, is a period drama about three siblings' quest for revenge during the economic boom of 1970-80s Korea, as their fates play out against a larger tide of power, money, politics, and the growth of a city.
[1][2] History of a Salaryman (2011-2012), starring Lee Beom-soo, Jung Ryeo-won, Jung Gyu-woon, Hong Soo-hyun, Lee Deok-hwa and Kim Seo-hyung, is a quirky comedy and murder mystery about an ordinary salaryman who finds himself involved with corporate spies and rival pharmaceutical companies, and also a parody of modern office politics using the historical events during China's Chu–Han Contention as satire.
[3][4] Jang, Jung, and Yoo also worked together on the less successful Incarnation of Money (2013), which starred Kang Ji-hwan, Hwang Jung-eum, Park Sang-min, Choi Yeo-jin, Oh Yoon-ah and Kim Soo-mi, and focused on the greed and corruption in Korean society involving prosecutors, lobbyists and loan sharks.