&gt; I&#x27;d imagine it being pretty unsettling to watch a bank balance fluctuate.<p>Banks have generally solved this by batching updates, but yes, it could be unsettling for the customer in a similar situation.  There are ways around that though, for example you update a cache that stores the data instantly and then let the eventually consistent source of truth update the cache again if it is not in sync, or perhaps have a short timeout on the cache, so the customer gets a consistent and smooth experience but the source of truth is still accurate, eventually.