Randy Merrill is an American mastering engineer who has worked with international artists including DAY6, Lady Gaga, Katy Perry, Maroon 5, Harry Styles, One Direction, Adele, Imagine Dragons, Beck, Liam Gallagher, Jonas Brothers, Muse, Cage the Elephant, Maren Morris, Ariana Grande, Mumford & Sons, Paul McCartney, Troye Sivan, Taylor Swift, Lorde, Justin Bieber, Porter Robinson, BUCK-TICK, King Gnu, Little Mix and BTS.