  We present an attempt to closely mimic the initial stage of heavy ion
collisions within holography, assuming a decoupling of longitudinal and
transverse dynamics in the very early stage. We subsequently evolve the
obtained initial state using state-of-the-art hydrodynamic simulations, and
compare results to experimental data. We present results for charged hadron
pseudo-rapidity spectra and directed and elliptic flow as functions of
pseudo-rapidity for $\sqrt{s_{NN}}=200\,{\rm GeV}$ Au-Au and $2.76\,{\rm TeV}$
Pb-Pb collisions. The directed flow interestingly turns out to be quite
sensitive to the viscosity. The results can explain qualitative features of the
collisions, but the rapidity spectra in our current model is narrower than the
experimental data.
