His first solo work was DIY self-releases on Bandcamp before his label debut, DSU (2014), released on Orchid Tapes to critical acclaim from various publications.

In 2022, Alex scored American director Jane Schoenbrun's film We're All Going to the World's Fair, and later released his ninth album, God Save the Animals.

[4] In 2011, Giannascoli enrolled at Temple University, where he studied English in hopes of becoming a teacher, eventually dropping out to pursue a career in music.

[2][6][7] After self-releasing various albums, EPs, and singles on Bandcamp from 2010 to 2012, Giannascoli's popularity spread through word of mouth, blogs, and reverence by other musicians.

"[4] This led to Orchid Tapes signing Giannascoli to its roster, as well as the release of his label debut DSU (2014),[4] which garnered acclaim from music critics.

[11] The following year, Giannascoli worked with Frank Ocean on his albums Endless and Blonde, providing guitars and arrangements for several songs.

[20] In June 2020, he dropped "(Sandy)" from his stage name, returning to going by Alex G.[21] Giannascoli scored the film We're All Going to the World's Fair, released on April 8, 2022.

[4] The Philadelphia Inquirer praised him as "a particularly gifted melody writer" whose "fuzzy, sometimes distorted songs, which hark back to slightly askew 1990s bands such as Pavement, can't hide his skill as a pop craftsman and a constructor of elliptical narratives that call for repeated listening.

"[6] Despite being formerly hesitant to record his music in professional studios, Giannascoli's God Save the Animals was studio-recorded with help from Jacob Portrait during the Covid-19 pandemic.