  The CMS electromagnetic calorimeter (ECAL) is a high-resolution, hermetic,
and homogeneous calorimeter made of 75,848 scintillating lead tungstate
crystals. Following the discovery of the Higgs boson, the CMS ECAL is at the
forefront of precision measurements and the search for new physics in data from
the LHC, which recently began producing collisions at the unprecedented energy
of 13 TeV. The exceptional precision of the CMS ECAL, as well as its timing
performance, are invaluable tools for the discovery of new physics at the LHC
Run 2. The excellent performance of the ECAL relies on precise calibration
maintained over time, despite severe irradiation conditions. A set of
inter-calibration procedures using different physics channels is carried out at
regular intervals to normalize the differences in crystal light transparency
and photodetector response between channels, which can change due to
accumulated radiation. In this talk we present new reconstruction algorithms
and calibration strategies which aim to maintain, and even improve, the
excellent performance of the CMS ECAL under the new challenging conditions of
Run 2.
