IT challenges of Gaia's Astrometric Global Iterative Solution

The Astrometric Global Iterative Solution (AGIS) scheme is the key process in the astrometric reduction of the Gaia data. It's main purpose is to generate the astrometic part of the Gaia catalogue in a way that optimally combines all 10^12 available measurements in a globally, self-consistent manner.We will outline the technical design and chosen approaches for the distributed processing infrastructure of AGIS. An important aspect in this is the efficient reading and passing of observation data to the mathematical core algorithms.