Concentric rings and gaps are commonly observed in protoplanetary disks. The favored mechanism for creating these substructures is planet-disk interactions, in which growing planets carve gaps in the disk, and drifting pebbles become trapped at the gap edges. Since the particle density at these gap edges can become much higher than the global value, they are likely sites for planetesimal formation via the streaming instability. In this talk, I will discuss the formation and fate of such planetesimals formed at planetary gap edges, as well as the effects this process can have on disk evolution and planet formation.