Explain how you would handle eventual consistency issues in a multi-region deployment.

Multi-region eventual consistency strategies: 1) MongoDB Multi-region Atlas: use write concern majority on primary region. Cross-region replication is asynchronous. Accept that secondary region may be slightly stale. Set maxStalenessSeconds on replica read preference. 2) Cassandra multi-DC: EACH_QUORUM for operations requiring global consistency (expensive). LOCAL_QUORUM for operations fine with D