Database Sharding: When Does it Make Sense?

hey everyone, ive been thinking a lot about scaling our databases recently. we're hitting some limits with our current setup, and sharding seems like the next logical step. but it also feels like a big architectural change. what are your experiences with implementing database sharding? what were the key indicators that told you it was time to shard, and what were the biggest challenges you faced? are there specific types of workloads or data patterns that make sharding particularly effective or, conversely, more painful?