In this talk I will discuss a recent approach to compute the genus-0 contribution to the four-point function of half-BPS operators in N=4 Super-Yang Mills, conjectured to be dual, via AdS/CFT, to the tree-level scattering of four closed superstrings in AdS_5 x S^5. Mellin space techniques, flat space limit, large p limit and data about the spectrum of two-particle operators heavily constraint its \alpha' expansion.
The results exhibit an intriguing similarity with the Virasoro-Shapiro amplitude in flat space yet to be fully understood.