Kye Beom-ju (Korean: 계범주, born November 8, 1991), better known by the stage name Bumzu (범주), is a South Korean singer, songwriter, and record producer. Bumzu is best known for writing and producing much of the discographies of boy bands NU'EST and Seventeen.

In 2024, he was the recipient of KOMCA's Grand Prize, having been the highest-earning songwriter for K-pop in 2023.

Bumzu grew up in Seoul, and learned the violin as a child. By the age of high school, he became active in Hongdae's underground music scene. His first mainstream work was composing for H.O.T's Jang Woo-hyuk's "Don't Go, Go Away" in 2011. He then participated in the singing competition show Superstar K 4 at the age of 22, which has been noted as his big break. Following the show, he began producing songs for Pledis artists including After School and NU'EST, and has produced songs alongside Woozi for Seventeen since their debut song "Adore U".

Since 2020, he has been the co-CEO of the music production company Prismfilter Music Group.

In 2024, Bumzu became the primary music producer for new group TWS under the pseudonym "Wasurenai". In February, he was awarded KOMCA's grand prize, having been the highest-earning songwriter for K-pop in 2023.

Credits are adapted from the Korea Music Copyright Association unless otherwise specified.