Her work is known for its brash take on pop music and is distinguished by experimental sound design, "sugary" synthesized textures, and incorporation of underground dance styles.

She worked closely with artists from the PC Music label, including A. G. Cook and GFOTY, and also produced for acts such as Charli XCX, Vince Staples, Kim Petras, Madonna, Hyd, Gaika, and Namie Amuro.

[11] A self-titled second studio album, reportedly "nearly finished" at the time of her death and completed by her brother Benny Long, was released posthumously in 2024.

[9] Sophie said in an interview published by Lenny Letter, "[My dad] had brilliant instincts, taking me to raves when I was very young.

[14] At the age of approximately nine or ten, Sophie expressed the desire to drop out of school to become an electronic music producer, but was not allowed to.

[14][15] Sophie's music career began in a band named Motherland, alongside bandmates Sabine Gottfried, Matthew Lutz-Kinoy, and Marcella Dvsi.

[24] Sophie became involved with artists affiliated with the PC Music label after encountering Dux Kidz, a project between A. G. Cook and Danny L Harle.

[19] The single, featuring vocals from UK singer Jaide Green, consisted of two mixes of the titular track (titled the "Dub" and "Vox"), as well as the B-side, "Eeehhh", which was initially posted on (and later deleted from) her SoundCloud in 2011.

[21] "Bipp" in particular, featuring vocals from Sophie's former Motherland bandmate Marcella Dvsi, received considerable attention from music critics, topping XLR8R's year-end list and placing 17 on Pitchfork's.

[34] "Lemonade" and "Hard" placed 68th and 91st respectively on the 2014 Pazz & Jop critics poll, and the single was included in the top ten of year-end singles lists by The Washington Post, Resident Advisor, Complex, and Pitchfork;[35][36][37][38] "Hard" was included in the top ten on lists by Dazed and Dummy.

[47] In late 2016, Sophie acted as an additional producer on Charli XCX's song "After the Afterparty" and cameoed in the single's official music video.

[49] Sophie collaborated with producer Cashmere Cat on several tracks from his album 9, including "Love Incredible" alongside Camila Cabello and "9 (After Coachella)" with MØ.

[53][failed verification] On 1 May 2018, an interview with Crack Magazine revealed that the official album title is Oil of Every Pearl's Un-Insides.

[66] AllMusic wrote that Sophie's "sophisticated, hyperkinetic productions" feature a "surrealist, blatantly artificial quality", typically making use of "sugary synthesizer textures, and beats drawing from underground dance music styles" as well as "experimental sound design" and feminine vocals.

"[68] Pitchfork credited her work with "mold[ing] electronic music into bracingly original avant-garde pop".

[72] Apart from vocals, Sophie created original synthesized sounds from the elementary waveforms by using the Monomachine, eschewing the use of samples.

[34] Likening the construction of a track to building a sculpture out of different materials, she synthesized sounds resembling "latex, balloons, bubbles, metal, plastic, [and] elastic".

[34][72][73] Tiny Mix Tapes described her production as "liquid metal or maybe the noise equivalent of non-Euclidean geometry".

[75] Sophie's early visuals came from a series of colourful images described as "Homemade Molecular Cooking",[21] with the singles' cover art often depicting objects made from plastic or other industrial materials, an idea that originated from discussions with John Roberts, a fellow electronic musician.

Early in her career and prior to coming out as transgender, Sophie's real-life identity was the subject of press speculation.

[21][30] At one Boiler Room show, drag performer Ben Woozy was recruited to mime a DJ set as Sophie while the artist posed as a bodyguard.

[51] Sophie confirmed a trans identity in subsequent interviews, also speaking of feeling boxed-in by labels and describing music as "my chosen method of communication" and self-expression.

[78] On 30 January 2021, at the age of 34, Sophie fell three floors from the rooftop of a building in Athens, Greece while attempting to take a picture of the full moon.

[81][82] Artists including Rihanna, Sam Smith, Vince Staples, Charli XCX, A. G. Cook, and Rahim Redcar expressed their condolences.

An accompanying video uploaded to YouTube Shorts, titled "Celebrating Sophie Xeon", uses her track "Immaterial" from her first studio album Oil of Every Pearl's Un-Insides.