The biggest issue faced with DynamoDB from my perspective has been the problem with any hosted service - that is, the operational stability is in the hands of others entrusted with operating a massive multi-tenant system, and any outage cannot follow your own operational recovery mechanisms unless you plan for failover yourself. And the moment you plan for failover, you need to evaluate why you don't just handle the…
There are many things people justifiably complain about DynamoDB, but operational support has rarely been one of them.
Such an outage can sometimes be mitigated when operations are internal to a company; but with DynamoDB, one has to build internal failover or implement a complex cross-region replication scheme. The complexity and reliability starts to reduce the attractiveness of the hosted service in general.