This article series reconceptualizes consensus systems, moving beyond the traditional Paxos and Raft algorithms. It introduces pluggable durability, a system where durability rules can be specified with plugins, allowing for more flexibility in deploying nodes without affecting performance. The series also redefines leadership change as a two-step process: revocation and establishment, offering multiple methods to achieve this goal. Additionally, it discusses handling races, completing and propagating requests, and the implementation of Vitess, which utilizes these flexibilities to provide a scalable and efficient consensus system.