Understanding the photo-physics of driven materials requires detailed measurements of multiple microscopic degrees of freedom at ultrafast time resolution. Femtosecond X-rays are key to this endeavor, as they can probe the dynamics of structural, electronic and magnetic degrees of freedom. To this end, we perform hard and soft x-ray diffraction experiments aimed at clarifying the mechanisms behind photo-induced phases. While traditional diffraction experiments reveal insights on long range orders, time-resolved resonant inelastic x-ray scattering gives access to the dynamics of the momentum-dependent excitation spectrum of a material. This is key in revealing precursors of long-range orders, such as magnetic correlations. In addition, femtosecond x-ray techniques also allow for probing excitations directly in the time domain. The diffuse scattering between Bragg peaks yields momentum-resolved information on phonon anharmonicities and was key in determining possible pathways to light-induced ferroelectricity. We perform these experiments at several free-electron laser facilities around the world such as PAL-XFEL in Korea, LCLS in the United States, European XFEL in Germany, and SwissFEL in Switzerland.