  In the course of the past several years holography has emerged as an ab
initio tool in exploring strongly-time-dependent phenomena in gauge theories.
These lecture notes overview recent developments in this area driven by
phenomenological questions concerning applicability of hydrodynamics
(hydrodynamization) under extreme conditions occurring in ultrarelativistic
heavy-ion collisions at RHIC and LHC. The topics include hydrodynamization time
scale, holographic collisions, as well as hydrodynamization from the point of
view of the asymptotic character of the hydrodynamic gradient expansion. The
emphasis is put on concepts rather than calculational techniques and a
particular attention is devoted to present these developments in the context of
the most recent advances and some of the open problems.
