  The Precision Proton Spectrometer (PPS) started operating in 2016 and has
collected more than 110 fb$^{-1}$ of data over the course of the LHC Run 2, now
fully available for physics analysis. This contribution covers the key features
of the PPS alignment and optics calibration, which have been developed from
scratch. The reconstructed proton distributions, the performance of the PPS
simulation and finally the validation of the full reconstruction chain with
physics data (dilepton events) are also illustrated.
