The base is original from the producer (chords and melodies), but is complemented with elements that complement the song that come from samplepacks, usually, vocal chops, guitars, wobbles sections, glitch effects. It is the standard in which most of producers work, in a project you will find MIDI files made by the producer, but also melodic loops.
The guitar melodies are made with a kontakt library, and there are some counter melodies with vocal chops.
Instrument Vocal Chop
Sample pack Cymatics - Euphoria
Loop name Cymatics_-_Euphoria_Vocal_Chop_22