##### ###### ##### ### # # ### # # ###### ## ## ## ## ## ## ## # # # # # ## ##### #### ##### # # # # # # # #### ## # ## ## ## ## # # # # # ## ## # ###### ## ### # ### # ######
##### ###### ##### ### # # ### # # ###### ## ## ## ## ## ## ## # # # # # ## ##### #### ##### # # # # # # # #### ## # ## ## ## ## # # # # # ## ## # ###### ## ### # ### # ######
Twitter's Snowflake: -bit ID = bit unused + bits timestamp + bits machine ID + bits sequence.
bits timestamp = years from epoch. bits = machines. bits = IDs/millisecond/machine.
IDs are time-sortable. Clock sync matters: NTP keeps machines within milliseconds. Handle clock skew by waiting or rejecting.
