[9] In 2006, Petras, then aged 13, appeared on a German television current-affairs show in which she discussed her medical gender transition.

These appearances resulted in international media coverage of her transition, touting her as the "world's youngest transsexual".

[13] She was evaluated by the head of the psychiatric unit at Frankfurt Hospital, Bernd Meyenburg, and approved for gender-affirming surgery at 16 years old.

[17] At 19 years old, Petras moved to Los Angeles, living in the garage of a producer in Redondo Beach.

[18] In 2013, Petras was featured on two singles named "Flight to Paris" and "Heartbeat" by German DJ Klaas.

Abraham, Stephen Dresser, Johan "Jones" Wetterberg, Edward Ellis, and Aaron Joseph on a music career, releasing demos on her SoundCloud page, including one titled "STFU".

In August 2017, Petras released her debut single "I Don't Want It at All",[21] The song went on to reach the Spotify Global Viral chart.

[22] The accompanying music video for the song premiered in October on Vevo, and features a cameo appearance by Paris Hilton.

"[24] During the end of 2017, Petras was dubbed "most likely to dominate the pop charts" by Paper magazine,[25] and appeared on Charli XCX's mixtape Pop 2 (2017) for the track "Unlock It" alongside Jay Park.In January 2018, the Nicholas Harwood-directed video for Petras's single "Faded", which features Lil Aaron, premiered on Noisey,[26] That same month, she appeared in the January issue of Galore.

Bryan Kress of Billboard noted how while the single is "still keeping Petras's upbeat, unabashed pop sound... [it] ventures into new territory for the songwriter.

The project was seen as a departure from Petras's typical sound, and features a guest appearance from the horror hostess character Elvira.

[33] In March 2019, Petras appeared as a headline act at the Sydney Gay and Lesbian Mardi Gras, noted as one of the world's largest pride festivals, which has been headlined by other notable acts including Kylie Minogue, Cher, Dua Lipa, Kesha, Sam Smith, The Veronicas[34] and George Michael.

In August, Petras announced that there would be a limited edition vinyl pressing of Turn Off the Light, Vol.

That same month, she announced that she would be the supporting act on the European leg of Camila Cabello's The Romance Tour,[40] which was cancelled due to the coronavirus pandemic.

In 2021, Petras was featured on remixes of several songs made popular on TikTok, including "Jenny" with Studio Killers, and "SugarCrash!"

In August 2021, Petras signed to Republic Records and released "Future Starts Now" as the lead single from her major-label debut studio album, Problématique.

[51] On 3 December 2021, after overwhelming fan response on TikTok, Petras released "Coconuts", doing so around a month earlier than scheduled.

On 10 February 2022, after teasing some of the songs on TikTok, Petras announced a surprise EP titled Slut Pop,[52] which was released the following day.

The track went viral on TikTok and hit number one in various countries upon release, including Australia, the United Kingdom, and New Zealand.

On 17 February 2023, she stated that an album that she had been working on "for three years" was ready to be released the next summer, sharing her excitement for people to hear the songs.

In anticipation of the album, the news was celebrated as part of a live performance on NBC's Citi Concert series.

[74][75] She credits the late 1990s and early 2000s pop scene,[76] as well as 1980s Italo disco,[25] as the primary basis for her sound.

[77] Petras's other inspirations include Katy Perry, Cher, Lady Gaga, Rihanna, Beyoncé, Britney Spears, Christina Aguilera, Madonna and the Spice Girls,[78][79][76] as well as Boy George, Debbie Harry, Queen, Freddie Mercury,[19] Judy Garland, Baby E, Lil Aaron, Liz Y2K,[27] and Kesha.

[85] Following the release of her debut mixtape Clarity (2019), many reviewers praised the record but criticized her involvement with Dr. Luke, who had been accused of sexually and verbally assaulting Kesha in 2015.