How Facebook engineers keep Messenger from crashing on New Year's Eve, when more messages are sent than on any other day, through "graceful degradation" (Amy Nordrum/IEEE Spectrum)

Amy Nordrum / IEEE Spectrum:
How Facebook engineers keep Messenger from crashing on New Year's Eve, when more messages are sent than on any other day, through “graceful degradation”  —  Messenger's 1.3 billion users send more messages on New Year's Eve than on any other day of the year