My main activity is to understand and simulate Warm Dense Matter at microscopic level, at the crossroads of solid states physics and plasma physics. Understanding matter in this regime is important to address technological challenges such as target optimization for inertial confinement fusion. Specialized in electronic transport properties (electrical conductivity, reflectivity, absorption), I have been using and participating in the development of the electronic structure calculation software, based on DFT, ABINIT for more than 20 years. We are one of the few teams to master the calculation of X-ray absorption spectra (XANES) in this thermodynamic regime. Massively parallel computers are widely used. All of my work is done in close collaboration with experimental teams whether they are in France or abroad.