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.
Process note
Diva, Sylenth, Serum and Kontakt were used to compose the track. For mix and master, FabFilter, Waves, Izotope, Brainworx, The glue and Endless Smile bundles were used.
Melodic loops
Instrument Pluck
Sample pack Audentity Records - Energetic Slap House
Loop name AUESH_126_Synth_Loop01_Plucks_Wet_Am