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 Nexus 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 Cello
Sample pack Sounds of KSHMR Vol. 3
Loop name KSHMR_Cello_07_Melody_100_Dm