Cosmology and Astrophysics from CMB secondary anisotropies

CMB observations aimed at studying Inflation, Dark Matter and Dark Energy are also a treasure trove of information about the Large Scale Structure between us and the surface of last scattering. I will discuss the synergies between upcoming Large-Scale Structure and Cosmic Microwave Background (CMB) experiments, and describe how information about the late-time Universe is imprinted on the small scale CMB. I will review some of the most important physical effects at play and I will focus on the Sunyaev-Zel'dovich (SZ) effect and weak gravitational lensing, which use the CMB as a "backlight" to image the matter and gas in and around galaxies, as well as the epoch of reionization. I will present recent measurements that shine light on the feedback mechanisms in galaxy formation and that provide a resolution to the "missing baryons" problem. I will also discuss the most stringent cosmological constraints to date from the cross-correlation of CMB lensing and galaxy clustering and review the expected improvements with the next generation of experiments.