The existence of CP violation in the decays of strange and beauty mesons is well established experimentally by numerous measurements. By contrast, CP violation in the decays of charmed particles has escaped observation in the last decades. During the first two runs of the LHC, the LHCb collaboration has collected a sample of charmed hadrons of unprecedented size, enabling some of the most sensitive searches for CP violation ever performed. Finally, observation of CP violation, with a significance larger than 5σ level, has been announced by the LHCb Collaboration at Moriond EW 2019 in the measurement of the time-integrated asymmetry in D0 → K−K+ and D0 → π−π+ decays, performed using the full data set collected by LHCb so far, which corresponds to an integrated luminosity of 9 fb−1. A detailed discussion of this result is presented here.