My background is in physics in computer science. I am a member of the Gaia SOC development team and lead the development of AGIS (Astrometric Global Iterative Solution). This is one of the larger software system that is being developed at ESAC for Gaia and will give us the astrometric catalogue. My science interests are related to Gaia: 1. Astrometry: Formation history, composition, and structure of the Milky-way. Will be able to study these topics in details with Gaia's astrometric data. 2. General relativity: Gaia will make a number of interesting contributions in this field. Two examples are the determination of some fundamental physical constants with high-accuracy and possible progress towards the detection of gravitational waves. 3. Self-calibration: Gaia's is called a self-calibrating mission. It means that that needed calibration parameters are treated initially as unknowns and are then determined as part of the normal data processing through AGIS.