When sharding is more trouble than it's worth. Like if you're dealing with really complex queries that touch multiple shards, it can get messy. Also, if your data just doesn't split up easily, or if you're only expecting a little bit of growth, sharding might be overkill. Sometimes a bigger server or better indexing is all you need, ya know?

We're seeing our main database slow down a bit. Sharding comes to mind, but I've read it can get really complicated operationally and isn't always the first thing you should do. So, when have you guys decided NOT to shard your database? What did you do instead to scale it up? Did you go for vertical scaling, use read replicas, or something totally different? I'm just looking for some real examples where sharding was on the table but you went another way.