Marco Daniel Borrero, known professionally as Mag, is an American record producer and songwriter born in Brooklyn. He is recognized for his significant contributions to Latin urban music, notably his work with Bad Bunny, including 15 tracks on the album 'Un Verano Sin Ti'. Mag has also collaborated with artists such as Rauw Alejandro, Bebe Rexha, Imagine Dragons, Demi Lovato, and Selena Gomez, showcasing his versatility across various genres.