I mean, you can rest assured that you will have problems with Vitess at some point. All software is buggy, and there is no guarantee one of those bugs won't be catastrophic. You should plan for a method to completely replace your entire production cluster in the event of failure. This can be quite difficult with horizontally-scaled databases. It's also not uncommon to hit a scaling limit for which there's no simple solution, or not be able to build out a replacement production cluster due to unplanned-for limitations.