  This thesis addresses the thermalisation of heavy-ion collisions within the
context of the AdS/CFT duality. The first part clarifies the numerical set-up
and studies the relaxation of far-from-equilibrium modes in homogeneous
systems. Less trivially we then study colliding shock waves and uncover a
transparent regime where the strongly coupled shocks initially pass right
through each other. Furthermore, in this regime the later plasma relaxation is
insensitive to the longitudinal profile of the shock, implying in particular a
universal rapidity shape at strong coupling and high collision energies.
Lastly, we study radial expansion in a boost-invariant set-up, allowing us to
find good agreement with head-on collisions performed at the LHC accelerator.
  As a secondary goal of this thesis, a special effort is made to clearly
expose numerical computations by providing commented Mathematica notebooks for
most calculations presented. Furthermore, we provide interpolating functions of
the geometries computed, which can be of use in other projects.
