In this contribution we summarize the highlights from the Pierre Auger Observatory presented at the 35th International Cosmic Ray Conference. We discuss the update of the measurement of the energy spectrum of cosmic rays over a wide range of energies ($10^{17.5}$ to above $10^{20}$ eV), studies of the cosmic-ray mass composition with the fluorescence and surface detector of the Observatory, the discovery of a large-scale anisotropy in the arrival direction of cosmic rays above $8 \times 10^{18}$ eV and indications of anisotropy at intermediate angular scales above $4 \times 10^{19}$ eV. Moreover, we report on tests of hadronic interactions beyond LHC energies, multi-messenger analyses with neutral primaries and the progress of the upgrade of the Observatory, AugerPrime, aimed at elucidating the origin of the observed flux suppression at ultra-high energies.