1. A method for performing event processing comprising: receiving, by an updater executed by a computer system, an input event from an input event stream, the updater having a slate associated therewith; deserializing a first serialization of the slate to generate a slate object; performing, by the updater, an update operation on the slate object using the input event; storing the slate object; receiving a request for the slate; in response to receipt of the request, retrieving the slate object and generating a second serialization of the slate; and returning the second serialization responsive to the request.