Los Angeles's Scission have been operating since 2013 at the boundary between metalcore and death metal, a crossover that captures both the precision and brutality of the latter and the structural intensity of the former. In a city as massive and competitive as LA, surviving over a decade in the underground speaks to the genuine quality of their craft.

Palm Springs, California's Shrine of Resurrection, formed in 2021, pursue progressive death metal filtered through metalcore's structural sensibility — ambitious compositions that balance technical complexity with the direct aggression of the modern heavy underground.

Los Angeles, California's Sinyells have built a sound since 2019 that layers industrial metal's mechanized, abrasive textures into a metalcore framework, producing music that feels digitally hostile and physically aggressive in equal measure.

Sleeping Giant formed in Redlands, California in 2006 by members of Christian metalcore act xDeathstarx, establishing themselves as one of the most prominent acts in the intersection of extreme metal and evangelical Christianity. The band released five studio albums between 2007 and 2017, including Sons of Thunder (2009) and Kingdom Days in an Evil Age (2011), consistently integrating direct worship themes into their aggressive metalcore instrumentation. Their music reached audiences well beyond the Christian metal circuit, and the band played their final show in February 2018. Sleeping Giant were notable for treating their faith not as a marketing angle but as the central premise of their live and recorded output.

Santa Paula, California band formed in 2019 that merges the aggression of death metal with metalcore structure, delivering a hard-hitting sound from the Ventura County underground.

Solus are a Los Angeles post-black metal project active since 2007, weaving atmospheric and introspective textures into a black metal foundation in the manner characteristic of the city's eclectic extreme metal underground.

Something Left Unsaid are a Pacifica, California metalcore band formed in 2012, operating in the Bay Area's active metalcore scene with a sound rooted in melodic aggression and post-hardcore song structures.

Soul Inside is a groove metal and metalcore band from Los Angeles, California, formed in 2018. They blend the rhythmic heaviness of groove metal with metalcore's aggressive riffing and dynamic song structures.

Spirotin is a Los Angeles band formed in 2021 that merges black metal and metalcore, combining the atmospheric malice and tremolo aggression of black metal with the rhythmic heaviness and breakdowns of metalcore.