Solid Oxide Fuel Cells (SOFC) is an interdisciplinary technology by excellence, necessitating combined knowledge and R&D from mechanical, chemical, electrical and materials science engineering. At LENI Laboratory at EPFL, SOFC cells and stacks are designed, tested and analysed in collaboration with industry, from small area single cells to now kW-range stacks integrated in a system. The hardware R&D effort is strongly assisted by, and dependent on, modeling activities, for both design (e.g. new geometries) and understanding (e.g. degradation phenomena). This modeling has to occur on different levels, from the electrochemistry on micron-scale, via fluid dynamics on mm-scale, to thermodynamic+economic optimization of an entire system on m-scale. The modeling, finally, is accompanied by validation experiments. The presentation will give an overview of the SOFC research status at LENI with application examples.