1. A method comprising: storing, in each of a plurality of geographically-separated data centers, data that includes at least first data items that are each associated with one or more particular accounts of a plurality of accounts; asynchronously replicating changes to the data from each data center of the plurality of geographically-separated data centers to each other data center of the plurality of geographically-separated data centers; receiving, from one or more clients, at a particular data center of the plurality of geographically-separated data centers, requests associated with a particular account of the plurality of accounts; responsive to determining, for a first set of one or more of the requests, that client interactions involving the particular account occurred within a last period of time at a first data center of the plurality of geographically-separated data centers: redirecting the first set of one or more of the requests to the first data center and servicing the first set of one or more of the requests from the first data center; responsive to determining, for a second set of one or more of the requests, that no client interactions involving the particular account occurred at any other data center of the plurality of geographically-separated data centers within the last period of time: servicing the second set of one or more of the requests at the particular data center; wherein the method is performed by one or more computing devices.