Backend & systems·Consistency and replication
every read is guaranteed to see the most recent committed write, so you never have to explain why the value went backwards.
Strong consistency
A model where reads reflect all prior writes, typically by routing reads to the leader or requiring a quorum. It removes an entire class of "it works on my replica" bugs and costs latency, availability during failover, and cross-region round trips. Most systems need it for a small subset of their data and treat the rest as eventually consistent.