Giant Impacts: Sculpting Planet Uniformity or Diversity?

The architecture, sizes and masses of multi-planet systems provide important clues to their formation and the origin of planetary systems in general. I will review proposed multi-planet formation scenarios and the role that giant impacts can play in sculpting these systems. I will show that, depending on planet composition, giant impacts can lead to planet size uniformity or diversity. I will conclude with highlighting and contrasting various planet compositions and formation scenarios that are currently consistent with observations of super-Earth and sub-Neptune populations.