DJing on a PS4 controller

Hi everyone,

In the past, I had an FLX4. It had good functions, but I didn't really like the quality. It broke and I returned it, got my money back. 

Now I spotted a youtube video where they used a PS4 controller as a DJ controller, but without a tutorial. Does anyone know how it works? If anyone knows, please tell me how I can also do it.

Thanks alot!
Steven