Esa Ruoho (born 26 October 1978 in Helsinki, Finland), better known as Lackluster, is a Finnish electronic music producer and performer from Kontula, Helsinki. He is also known as Esa Ruoho, XLLV, Can'O'Lard and Kökö and the Köks.
Ruoho has lived most of his life in Helsinki, Finland, but has also, since 2000, travelled to Regina, Saskatchewan, Canada for six months in 2000–2001, and also spent time in Dublin, Ireland.