She adopted the name in 2016 and independently released her debut single "Better Things", which Pip Williams, of The Line of Best Fit describes as, "Sharp, slick electro-pop with a hell of an attitude."

In the spring of 2009, Lang signed a publishing deal with Nettwerk One/H-Songs, who launched the careers of Sarah McLachlan and Coldplay and other world-renowned artists such as Shania Twain, Avril Lavigne, Chantal Kreviazuk.

In 2010, she independently released her debut album, The Underdog, which earned her two Canadian Radio Music Award Nominations (HOT AC & CHR) for her single "Mr. Immature".

[9] In 2010, Lang toured Canada nationally for her debut album, The Underdog, often performing at clubs and colleges and making various radio station appearances.

During that time, she opened for K'naan, Fefe Dobson, Simple Plan, Ron Sexsmith, Matt Good, Shawn Desman, and Sum 41.

Lang's vocals were featured on ISH's song "Rollin'" released on Warner Music, which also received airplay on Canadian radio that year.

She continued to focus on writing sessions while living in Bushwick, Brooklyn, and started to perform in clubs such as Rockwood Music Hall and The Bitter End, later releasing her EP Rubix in 2014.

Mitch Mosk of Atwood Magazine described Chapter 1: The Truth as "A gorgeous three-track collection of dynamic and intimately reflective dark indie pop."

[1] In 2019, Lang released a full-length album called Rings, which she wrote and co-produced with her husband Frequency (Eminem, Rihanna), written entirely about their marriage.

In a post by Wonky Sensitive, the blog refers to the album as "A collection of 10 heartfelt and deeply personal songs, Rings is a portrait of marriage - a glimpse of the highs, the lows, and everything in between.

Pulling inspiration from Beyoncé, Missy Elliot, The Black Eyed Peas, and Run the Jewels, Lang started crafting a new style incorporating her ability to talk-rap and sing full-range simultaneously.

She wrote and co-produced the EP Stef Lang_02 with her husband during the pandemic and released it in December 2020 and it was featured on playlists such as New Music Friday and Alternate R&B, amassing over a million streams.

About her songwriting process, she says, "My philosophy is to write real songs," often crediting influences like Kid Cudi and Robyn, whose themes of darkness and sadness have molded her music.