Has anyone done on-site with Palantir before?

I heard they ask systems design and decomposition interviews (and that those two are different). I am a new grad so I dont really know much in terms of systems design so how do I prepare for one to best succeed?

Can anyone share any info specifcially for the decomposition interview?

Secondary questrion: What would be most relevant for interviews: Grokking the Systems Design interview or Grokking the object oriented design interview? I can buy both ... but first asking for opinions.

Thanks!