Lately I've been trying hard to not just get idempotence but to get a full CRDT. While established CRDTs like an OR-set are great, simply framing a problem in t

Lately I've been trying hard to not just get idempotence but to get a full CRDT. While established CRDTs like an OR-set are great, simply framing a problem in terms of a max value has been really useful. Also useful are fuse values, where you record the first non zero value. Getting commutativity in addition to idempotence is great. Examples where this is useful tend to be pretty obvious in hindsight (things like accepting partially reported data, or recording a high water mark), and most people have built systems using these properties but taking a more formal approach has made it easier to identify and confirm that the order of operations doesn't need to be strict and at least once delivery is fine.