Large scale structure leaves an imprint in the cosmic microwave background (CMB) via gravitational lensing. In this talk, I will show that joint analyses of correlations between galaxy surveys and measurements of CMB lensing offer a promising route to tighter and more robust cosmological constraints with current and future surveys. I will present results from the analysis of cross-correlations between the Dark Energy Survey and CMB lensing measurements from the South Pole Telescope and Planck. I will focus on recent results from the analysis of two-point correlation functions between these surveys, and on the calibration of cluster masses. With the next generation of CMB and galaxy surveys coming online soon, joint analyses of galaxy survey and CMB lensing correlations are poised to become increasingly powerful and will play an important role in enabling future cosmological surveys to distinguish between possible hints of new physics and systematic errors.