Since releasing his first string of singles and EP in 2019, he has worked with artists such as Olivia Rodrigo, John Mayer, Noah Kahan, Tate McRae, Charlie Puth, Laufey, Role Model, Reneé Rapp, Omar Apollo, Selena Gomez, Jeremy Zucker, Blu DeTiger, Kenny Beats, David Kushner, Addison Rae, Glaive and Megan Thee Stallion, and has accumulated over a billion streams on his own music.

[4][8] Glantz then moved to Los Angeles to begin songwriting and producing for others and soon after he decided to write songs for himself and to pursue a career as an artist.

He has also written and produced songs for a number of other artists such as Role Model, Olivia Rodrigo, Tate McRae and Louis The Child.

[20] Alexander co-produced "Good 4 U" by Olivia Rodrigo with Dan Nigro[21] which was released on May 14, 2021, through Geffen and Interscope and debuted atop the Billboard Hot 100.

[22] Alexander released his debut album "Aftershock" in July 2022 which had no features but contained the lead single "Hate Me If It Helps" which was co-written by Olivia Rodrigo, "The Hardest Part" which featured background vocals from Chappell Roan and "RIP You and Me" which includes an outro piano solo from Charlie Puth.

Alexander served as the executive producer for Reneé Rapp's debut album Snow Angel which was released in August 2023.