Fixing a Slow Database: Work Up the Scaling Ladder Cheapest-First

The article argues that a slow database should be fixed in a deliberate order rather than jumping straight to sharding, which is costly. It recommends first confirming the real cause and adding indexes, then adding a cache such as Memorystore for repeated reads, then using read replicas for read-only traffic. Scaling the instance to a larger machine type comes next, with attention to brief restarts, replica sizing and retry logic. Sharding is reserved for cases where the single primary remains the write bottleneck, and measurement is advised at every step.