Thanks to the wealth of cosmological data accumulated in the last decades from astronomical observations and Cosmic Microwave Background experiments, there is strong evidence of the necessity for physics beyond the Standard Model. The purpose of my talk is to describe the virtues and difficulties of a particle physics embedding of the inflationary paradigm, and its connection to low-energy phenomenology. Specifically, I will introduce a supersymmetric Grand-Unified model that makes predictions for cosmic microwave background observables similar to those of the Starobinsky model of inflation, and incorporates a double-seesaw model for neutrino masses consistent with oscillation experiments and late-time cosmology, among other nice features.