Hi Dmansu,
What you need is an iPad compatible controller. The controller itself does not need to connect to spotify – that’s what your iPad will do.
Your signal path looks something like this:
Spotify -> iPad -> Controller -> Speakers
Therefore what you need is simply an iPad compatible controller – the controller is not the thing that connects to spotify and therefore the controller will not be advertised as working with spotify. If the controller is DJAY 2 compatible, it will talk to spotify.
You need to determine what kind of a controller you need for your workflow – do you need jogs? Do you need the ability to play other formats? Can it charge my iPad?
Work out the answers and then do some googling 🙂 A good plae to start might be the controller guide published on here every year, and simply just pick out the iPad compatible options and then figure out what will work for you.
Hope this helps,
bob6397