Beginning At the age of 11, Kim started out as a
trainee for
SM Entertainment for almost 10 years beginning in 2003. However, approval for her
debut did not happen, either with a group or as a soloist.
2016–2024: Songwriting and producing After graduating from college, Kim switched to songwriting and producing. During this time, she was invited to sing on the soundtrack of a
k-drama. While recording, she met a producer,
Shinsadong Tiger. He then invited her to write a song in his studio. Kim's songwriting "passion crystallized in 2017 when she attended her first SM Entertainment songwriting camp". which went on to top the US
Billboard World Digital Songs chart. It led to more opportunities to work with SM Entertainment. During the
COVID-19 pandemic, Kim co-wrote "
Drama" for
Aespa. She also helped co-produce the
Girl Crush K-pop Vocals sample pack for producing
K-pop songs. In 2022, she worked with Red Velvet again on the lead single "
Birthday". In 2025, Kim signed with
Prescription Songs, an independent music publisher founded by
Dr. Luke.
2025–present: KPop Demon Hunters and further success In April 2025, it was announced that Kim would be featured on
the soundtrack of the
Netflix film
KPop Demon Hunters. She also wrote several of the songs on the soundtrack. Director
Maggie Kang attributed Kim's
demos as one of the reasons the film was
greenlit; Kim explained she had co-written and recorded "most of the demos" for the film when the directors then asked her to be the official singing voice for the character Rumi. The film received positive reviews for its soundtrack. The soundtrack also charted at number one on the
Billboard 200. One of the songs she co-wrote and performed, "
Golden", topped the
Billboard Hot 100. On "Golden" composition,
Ars Technica commented that the song "spans an impressive three-octave range, eventually hitting an A-5 on the chorus–a high note usually reserved for classically trained
operatic sopranos" and Kim's "performance on this song has impressed a lot of YouTube vocal coaches".
The Korea Herald similarly highlighted Kim's "Golden" performance, noting "the result is both technically impressive and emotionally resonant, a combination that has resonated with audiences far beyond the film". Kim is credited on three of these charting songs; in addition to "Golden", Kim co-wrote and performed "How It's Done" and co-wrote "
Your Idol". In July 2025,
YouTube channel Studio USOG announced Kim will contribute a song to the "Another Day of Debut Training" project, with all profits being donated to descendants of
Korean independence activists. On August 14, 2025, the group formed through the web series,
TDYA, debuted with the song "Keep the Light" composed by Kim and performed the song for the first time the following day at
Gwanghwamun Square in
Jongno-gu,
Seoul in a set of performances celebrating the 80th
National Liberation Day of Korea. On October 4, 2025, Kim announced her debut solo single, "
In Another World," which was released on October 24. On the night of October 4, she along with her fellow
KPop Demon Hunters cast-mates
Audrey Nuna and
Rei Ami made a cameo appearance on the
season 51 premiere of
Saturday Night Live in a sketch based on the film, reprising their respective roles as Rumi, Mira and Zoey. On October 7, they together performed "Golden" live in full for the first time on
The Tonight Show Starring Jimmy Fallon. On October 22, Kim signed with
WME. She then featured on the single "Out of My Body" from the upcoming deluxe edition of
Anyma's third studio album
The End of Genesys, which was released on December 19. On December 25, she and the other voices of
Huntrix performed "
12 Days of Christmas" at the Snoop Dogg 2025 NFL Halftime Show. On February 6, 2026, she released her second single "
Time After Time." On April 10, 2026, she and the other voices of Huntrix appeared during
Katseye's
Coachella 2026 performance as surprise guests and performed "Golden" alongside Katseye. ==Personal life==