Instagram Founder Kevin Systrom -- Take a Picture, I'm a DJ Now!

Kevin Systrom -- who co-founded Instagram and then sold it to Facebook for $1 billion -- isn't just a tech-genius, he also moonlights as a DJ ... and we have pics to prove it.

Systrom was in Las Vegas last night, partying his face off with about 30 of his new FBook buddies -- when he started DJ'ing a set at Rain Nightclub in the Palms Hotel.

This isn't Systrom's first go at spinning records -- he reportedly moonlit as a DJ back in his Stanford days.