Are neutrinos their own antiparticles? What is their mass scale? What is the origin of the matter-antimatter asymmetry in the Universe? Neutrinoless double beta decay (0𝜈𝛽𝛽), a lepton number violating process, could help answer these questions. Current limits on the decay half-life far exceed the age of the Universe: its rarity poses major experimental challenges. After a brief overview of the current landscape of 0𝜈𝛽𝛽 searches and the leading techniques in the field, this seminar will discuss the challenges faced and milestones achieved by the CUORE collaboration with cryogenic calorimeters. CUORE (Cryogenic Underground Observatory for Rare Events) is a tonne-scale experiment steadily taking data underground at the Laboratori Nazionali del Gran Sasso in Italy since 2017. With nearly a thousand TeO2 crystals operating a few millikelvin above absolute zero and more than 3 tonne · years of TeO2 exposure accumulated to date, CUORE has firmly established cryogenic calorimetry as a leading technology for rare-event searches in ultra-low-radiation environments. I will present a summary of CUORE latest results, highlighting major improvements in the data analysis. These achievements, along with the detector unprecedented cryogenic performance, pave the way toward CUPID, next-generation experiment based on scintillating cryogenic calorimeters for particle identification and enhanced sensitivity.