CRDTs: How Distributed Systems Agree Without Asking Permission

Introduction Picture two doctors updating the same patient record at the same time - one in São Paulo, the other in London. Both are offline. When connectivity returns, whose changes prevail? This is not a hypothetical. It is the everyday reality of distributed systems: multiple nodes, no shared clock, no guaranteed network. The conventional answer has long been locking - one node waits while another writes. But locks are fundamentally incompatible with availability. When the network is unreliab