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 beat is based on a Melody of cymatics pack on the piano and some plucks that together make a very characteristic sound. This added with the 808 below results in a beat with a catchy and super recognizable melody.
Sample pack Cymatics Oracle Various
Loop name Cymatics Oracle Varius MIDI 14