The striking discovery that the Cosmic expansion is not slowing down but accelerating has established as one of the puzzles in Cosmology sparking large observational campaigns across cosmic time to map the Large Scale Structure and geometry of the Universe. The Dark Energy Survey is perhaps the largest operating survey spanning 5000 deg2 up to redshift one, measuring ~ 300 million galaxy positions and shapes, the light-curves of few thousand supernovae, and the masses of tens of thousands of galaxy clusters. In this talk I will review the probes that these surveys use to test our cosmological model, such as galaxy clustering and weak lensing, discussing current constrains and their implications, including the latest cosmological results from the first year of DES observations.