In the context of LHC Run-2, the Compact Muon Solenoid (CMS) detector was upgraded. In particular, the CMS trigger system and particle reconstruction were improved. The CMS experiment implements a sophisticated trigger system composed of a Level-1 trigger, instrumented by custom-designed hardware boards, and software layers called High-Level-Triggers (HLT). A new Level-1 trigger architecture with improved performance has been installed and is now used to maintain the thresholds used in LHC Run-1 in the more challenging conditions experienced during Run-2. Optimized software selection techniques have also been developed at the HLT. The hadronic τ reconstruction algorithm has been modified to better account for the π0(s) from τ decays. In addition, improvements to discriminators against QCD-induced jets and electrons were also developed. The results of these improvements are presented and the validation of the τ identification performance is shown.