Reorganization processes in dense active matter remain a central open question in non-equilibrium physics. In this talk, I will discuss how highly persistent self-propulsion drives local rearrangements in dense active assemblies, and how these rearrangements can cascade into system-spanning avalanche events. Using large-scale numerical simulations, we study dense systems of self-propelled particles that evolve through a sequence of mechanically stable configurations punctuated by sudden collective failures. I will present a systematic characterization of avalanche statistics as a function of system size and activity protocol, and show how the microscopic nature of the propulsion mechanism controls the scaling of avalanche sizes, as well as their frequency and temporal organization. Overall, these results provide a unified perspective on the interplay between persistent activity, mechanical stability, and avalanche dynamics in dense active matter. I will conclude by presenting recent results on active jamming.