You can check [Mini Review] Giving up on Crystal for some cons.
Exact problems mentioned there are debatable, but the points in general are (imho) truthy.
- Type system. Background with strongly typed languages will help, but there still will be times when you are fighting against type system.
- The rest of mentioned there points. IDE aren’t clever, compile times could be several seconds, i can’t agree with documentation (IMHO it’s awesome) but maybe I was just lucky, breaking changes occurs, future is uncertain.