We have applied the phenomenological model of diffused interfaces, developed originally to describe the Fe growth on Bi2Sr2CaCu2O8, to interpret quantitatively the core photoemission spectra of two reactive interfaces, namely Cr and Ge on Bi2Sr2CaCu2O8. At room temperature the interfaces with Fe and Cr have the same kinetics of growth suggesting similar adatom condensation, while the semiconductor-superconductor interface grows layer-by-layer according to the Franck-van der Merwe kinetics. Differences in the parameters of the model resulting from the simultaneous fit of the core-level decays are related to differences in the microscopic processes occurring during the growth.