A computer-implemented method, comprising: determining a first event of a sequence of events that are received as part of an event stream by: starting a timer; receiving a set of events of the sequence of events until the timer expires; re-sequencing the set of events in chronological order; and identifying the first event as an event of the re-sequenced set with a latest timestamp; initializing a value of an event counter with a timestamp of the first event; processing additional events of the sequence of events of the event stream, wherein the additional events are events of the sequence of events other than the first event; identifying that a particular event of the event stream has been filtered by an upstream stage in multi-stage processing; generating a skip-beat for the particular event that has been filtered, wherein the skip-beat is a dummy event inserted into the event stream as a replacement for the particular event that has been filtered; inserting the skip-beat into the event stream; receiving subsequent events of the sequence of events of the event stream, wherein the subsequent events are events that are received as part of the event stream after the insertion of the skip-beat; identifying an out-of-order event of the event stream; and processing the subsequent events in order of the timestamp associated with each of the subsequent events independent of whether each incoming event is an actual event or a skip-beat, wherein an actual event comprises event data corresponding to the event stream and is not a skip-beat. determining a first event of a sequence of events that are received as part of an event stream by: starting a timer; receiving a set of events of the sequence of events until the timer expires; re-sequencing the set of events in chronological order; and identifying the first event as an event of the re-sequenced set with a latest timestamp; starting a timer; receiving a set of events of the sequence of events until the timer expires; re-sequencing the set of events in chronological order; and identifying the first event as an event of the re-sequenced set with a latest timestamp; initializing a value of an event counter with a timestamp of the first event; processing additional events of the sequence of events of the event stream, wherein the additional events are events of the sequence of events other than the first event; identifying that a particular event of the event stream has been filtered by an upstream stage in multi-stage processing; generating a skip-beat for the particular event that has been filtered, wherein the skip-beat is a dummy event inserted into the event stream as a replacement for the particular event that has been filtered; inserting the skip-beat into the event stream; receiving subsequent events of the sequence of events of the event stream, wherein the subsequent events are events that are received as part of the event stream after the insertion of the skip-beat; identifying an out-of-order event of the event stream; and processing the subsequent events in order of the timestamp associated with each of the subsequent events independent of whether each incoming event is an actual event or a skip-beat, wherein an actual event comprises event data corresponding to the event stream and is not a skip-beat. <EOS>