Her 2019 album Pang featured an avant-pop sound and was released to critical acclaim, with the single "So Hot You're Hurting My Feelings" receiving viral attention.

Polachek has worked extensively with other artists, collaborating with Blood Orange, Fischerspooner, Charli XCX, Oneohtrix Point Never and Flume, as well as writing material for Beyoncé ("No Angel").

[5] Her family relocated to Tokyo, Japan, where she lived between the ages of one and six,[6] and later settled in Greenwich, Connecticut, where Polachek started singing choir in the third grade.

[7][10] As a teenager, she began traveling to New York to attend concerts, which were a mix of post-hardcore emo, DIY punk, and jazz shows.

[19] She sang vocals directly into her computer's built in microphone, making use of hotel closets, quiet airport gates, and spare dressing rooms during Chairlift's world tour.

[13] In early 2014, Polachek composed and produced instrumental scores for designers Proenza Schouler and Tess Giberson to be featured on runways and promotional videos.

[20] In April, she scored a live performance piece by artists India Menuez and Hayden Dunham at SIGNAL gallery in Brooklyn.

[21] In October, Polachek scored "HappyOkay", a ballet performance video directed by Elena Parasco and produced by House of Makers and Last Hour.

In a press release, Polachek announced that the single was the beginning of a new project, made mostly in collaboration with PC Music member Danny L Harle.

[31] On July 14, 2021, Polachek released the single "Bunny Is a Rider", another collaboration with Harle; she told Crack magazine that the song was part of a future project.

[53][54][55][56] Shaad D'Souza of The Guardian wrote: "Before 'Running Up That Hill' returned to the charts, Polachek was shaping up to be something like Gen Z's Kate Bush – a producer and vocalist interested in music that's formally eccentric and unapologetic about her own too much-ness.

[7] Polachek says that she "grew up kneeling at the altar of alternative music" and that Björk, Kate Bush, and Fiona Apple were her "absolute heroes" when she was a teenager.

[32] She called Paddy McAloon of Prefab Sprout her "favorite lyricist"[58] and stated that she is "very inspired by contemporary artists like Rosalía or Doja Cat, who play with sounds".

[62] In 2008, Polachek formed Girl Crisis choir with twelve other female singers, including members of Au Revoir Simone and Class Actress.

The modular group arranged and recorded two cover versions a year from 2008 to 2013, including songs by Black Sabbath, Nirvana, Leonard Cohen, the Bangles, and Ace of Base.

[63] In 2010, Polachek joined Jorge Elbrecht of Brooklyn-based Violens to record a "sgin" of Justin Bieber's "Never Let You Go": "We went on YouTube to find a video among the highest ranks of hits, and came across 'Never Let You Go'.

[73] Due to her production and engineering work on the song, Beyoncé's nomination for the Grammy Award for Album of the Year at the 57th ceremony included Polachek.

[77] In 2018, Polachek featured on Felicita's version of the traditional Polish song "Był sobie król", released on their debut studio album Hej!

[78] In 2020, Polachek featured on "La vita nuova" by Christine and the Queens and made a guest appearance in the short film around the EP of the same name.

[81] On November 4, 2021, Charli XCX released "New Shapes" featuring Christine and the Queens and Polachek as the second single from her studio album Crash (2022).

[82] In March, she was featured on Australian electronic music producer Flume's single "Sirens",[83] released ahead of his upcoming studio album Palaces.

[3] In October 2023, Polachek co-signed a publicized open letter to President Joe Biden, urging him to call for a ceasefire in the Israel–Hamas war.