Ari Staprans Leff was born in San Francisco, California. His father, Stuart Leff, is Jewish, and his mother, Silvija Staprāns, is Latvian. He spent his early childhood in a suburb of Atlanta, Georgia, and then his family relocated to a suburb of Philadelphia, Pennsylvania. During his time in high school, he played in several bands and studied jazz before moving on to electronic music. After graduating high school, Leff decided to pursue a behind-the-scenes role in music seeing that his career was not taking off. He chose to study music technology at New York University's Steinhardt School. He spent two of his four years at NYU as a studio intern for Jungle City Studios, where artists such as Jay-Z, Justin Timberlake, and Alicia Keys recorded. On May 19, 2017, Leff released the single "I Like Me Better", an up-tempo track inspired by his relationship that began shortly after he moved to New York City. As of March 9, 2021, the song has amassed over 1.1 billion streams on Spotify. In May 2018, Leff released I Met You When I Was 18 (The Playlist), a 17-track collection of new and previously released tracks, including the singles "I Like Me Better" and "The Other", that he had been working on over the course of a few years. Lauv released the single "I'm So Tired..." with Troye Sivan on January 24, 2019. They first met at a rehearsal space, and after writing another song that didn't work out, Lauv played Sivan the chorus of "I'm So Tired..." which he had written a few days prior. On March 6, 2020, Lauv released How I'm Feeling, unveiling three collaborations. "Who" with K-pop sensations BTS, "Canada" with Alessia Cara, and "El Tejano" with Sofia Reyes.