The contribution presents a brief summary of the Gauge/Gravity approach to the study of hydrodynamic flow of the quark-gluon plasma formed in heavy-io n collisions, in a boost-invariant setting (Bjorken flow). Considering the ideal case of a super symmetric Yang-Mills theory for which the AdS/CFT correspondence gives a precise form of the Gauge/Gravity duality, the properties of the strongly coupled expanding plasma are put in one-to-one correspondence with the metric of a 5-dimensional black hole with the horizon moving away in the 5th dimension and its deformations consistent with the relevant Einstein equati ons. Several recently studied aspects of this framework are recalled and put in perspective. New results in collaboration with G. Beuf and M. Heller on the early time expansion towards the hydrodynamical regime are provided giving a new insight on the far-from-equilibrium behaviour of the fluid at strong coupling and the thermalization and isotropization problems.