The 3D distribution of galaxies encodes a wealth of cosmological information, including on the nature of Dark Energy and the origin of the Universe's structure. The Dark Energy Spectroscopic Instrument (DESI) collaboration is in the process of producing the largest-ever map of this distribution by measuring galaxy redshifts. It is just over three years into its five-year survey and has already secured over 20 million redshifts --- a factor of 10 improvement on the total measured before DESI. This unprecedented achievement has been made possible by the ability to simultaneously measure 5000 redshifts at a time, using robots that can dynamically place an optical fiber to an accuracy of 2 microns. I will present the results of cosmological analysis on the first-year dataset. This will include the results from baryon acoustic oscillation (BAO) distance scale measurements and their implications for dark energy.