Spatially resolved spectroscopy is even more powerful when combined with magnification by gravitational lensing. I discuss observations of lensed galaxies at z≃2 with spatial resolution reaching 100 parsecs. Near-IR integral field spectroscopy reveals the kinematics, distribution and physical properties of star forming regions, and gas-phase metallicity gradients. Roughly two thirds of observed galaxies are isolated systems with coherent velocity fields, large velocity dispersion, multiple giant star-forming regions, and negative gas-phase metallicity gradients, suggestive of inside-out growth in gravitationally unstable disks. The remainder are undergoing mergers and have shallower metallicity gradients, indicating mixing of the interstellar gas via gravitational interaction. The metallicity gradients in isolated galaxies are consistent with simulations using standard feedback prescriptions, whereas simulations with enhanced feedback predict shallower gradients. These measurements therefore constrain the growth of galaxies from mergers and star formation as well as the regulatory feedback.