The covariant density functional theory (CDFT) is mature microscopic theory for studies in low-energy nuclear physics. In its framework the nucleus is described as a system of nucleons which interact via the exchange of different mesons. In my presentation, I will focus on recent studies of different nuclear phenomena across the nuclear chart and its extremes within the CDFT framework. I will start with the discussion of basic principles of this theory. Then I will consider cluster structures, ellipsoidal shapes and nuclear molecules in light nuclei and microscopic mechanism of their origin. This will be followed by the discussion of the impact of quasiparticle-vibration coupling on single-particle spectra in spherical nuclei and its consequences for tensor interaction. Statistical errors and systematic uncertainties will be considered next. Finally, the impact of beyond mean field correlations on the properties of the ground states and fission barriers in superheavy nuclei will be discussed.