Data loss in what sense? If you are using NoSQL, you'll have multiple replicas and data loss can often be reconstructed from Write Ahead Log. Even then due to n

Data loss in what sense? If you are using NoSQL, you'll have multiple replicas and data loss can often be reconstructed from Write Ahead Log. Even then due to network or memory corruption you might lose some data. But most startups who are using experimental database solution purely for performance/easy of use reasons often use Kafka and replay events when they lose data. Big companies like Google use replicated filesystem (GFS), Write Ahead Log to ensure migration/rebalancing are painless.