mongodb-replication-and-ha-readiness

Use when designing or hardening MongoDB replica-set topology and high-availability posture after the data model exists and reliability and data-architecture have set the availability and consistency targets. Produces replica-set member topology and election behavior, read-preference routing, write-concern selection that the topology can actually honor, arbiter posture, oplog-window sizing for failover, change-stream availability, and multi-region replica placement. Do not use for document modeling or shard-key choice, query tuning, backup/PITR, security/auth, or host/cluster provisioning; use the other Family B archetype skills (provisioning is infrastructure).