Age of Ascent is a massively multiplayer online (MMO) epic space game from Illyriad Games, powered by Microsoft Azure. An important and distinctive aspect of the game, which sets it apart from others of its genre, is its ability to have tens of thousands of players in a single concurrent world, engaged in huge battles and exploration. The underlying engine that powers it needs to be able to deliver this degree of massive scale, as and when needed, without any advance notice from the game community.
For more details on Age of Ascent see this detailed whitepaper on the game, which is available on the MSDN website,
There's also a blog by John Shewchuk that also goes into more detail about how Age of Ascent has progressed over time.