Consistency, Availability, and Consensus
The theory that governs distributed data, made practical — CAP stated correctly, PACELC, the full consistency spectrum with "what the user sees" examples, quorums, and Raft-style consensus without the proofs.
The theory that governs distributed data, stated correctly: CAP as a partition-time choice (not pick-2-of-3), PACELC, the consistency spectrum with what-the-user-sees examples, quorums, and consensus/Raft at an intuition level.