The key issue around which my research interests are constructed is a question of understanding the mechanisms of supernova explosion and the origin of gamma-ray bursts based on the analysis of observational data: spectra and light curves. Numerical modeling of non-equilibrium radiative and hydrodynamic processes in expanding supernova envelopes provides me the ability to study nucleosynthesis signatures in the optical light curves and spectra of faint supernovae, the origin of extremely metal poor stars, and supernova shock breakout phenomenon for mildly relativistic ejecta. All of this helps to answer on some pressing questions of stellar evolution and cosmology.