Not surprisingly, Facebook makes assumptions based on behavior to ensure that it propagates people and information with the highest likelihood of gaining attention or engagement.
When clients want to communicate with each other, they simply change their local copy of the data structure, and Firebase automatically ensures that the change propagates to other clients.
This relatively minor shift, the model found, still produces enough energy to initiate a wave-like pulse of crystal-shattering snow separation that quickly propagates uphill and leads to a major release of the upper layer.