Kai "Hiili" Hiilesmaa is the vocalist of the rock band The Skreppers, drummer of doom metal band KYPCK, former keyboardist of rock band Daniel Lioneye, as well as a respected producer from Finland. He has worked with several internationally recognized rock groups, including his near 20 year association with Finnish band HIM.

Hiilesmaa began producing music professionally in 1995, recording with such bands as HIM, Amorphis, and Apocalyptica. His trademarks include heavy, overdriven guitar sounds and experimental synthesiser programming. In 2013 Hiilesmaa addressed his preference for analog recording, "I prefer analog these days. Not only the sound, it asks more attitude to work with analog. Also you must make up your mind faster. There is no 'undo' in analog, which is often good.