Julia Michaels, from Bieber's songwriter to breakout star

The 23-year-old Iowa native's single "Issues" was one of 2017's biggest hits, and her songs "Sorry" for Justin Bieber and "Slumber Party" for Britney Spears proved her hit-making chops.


(Source: ABC News, https://www.youtube.com/watch?v=1AMGMuJ1R5M)