Recently, it has been shown that tree-level AdS boundary correlators for generic states can be expressed as a set of inverse differential operators, which have one-to-one correspondence to bulk-bulk propagators, acting on contact Witten diagrams. This novel form, dubbed as the differential representation, brings AdS boundary correlators into a close analog of flat space scattering amplitudes. Consequently, color-kinematics duality and differential relations among color-ordered correlators are identified for a variety of theories. We expect that the differential representation may provide a new way to manifest certain hidden structures in AdS boundary correlators and their putative dual CFT. I will end the talk by discussing a few future challenges, including double copy and notion of unitarity.