Financial transaction mission-critical messaging is used to securely transmit money without loss or duplication.  Transactions are afforded once and only once delivery.  If a transaction gets counted twice or gets missed, this is not a good messaging system.  Smartphones, the Internet of Things (IoT), and tablets depend on the availability of secure messaging.  Scalable, well-behaved applications data exchange is achieved with the availability of mission critical messaging.  
Systems are providing location-transparent means of transporting requests and answers between applications and data.   Leveraging information at opposite ends of a common wire depends on secure transmission capability.  Mission-critical middleware messaging is used to deal with the peculiarities of sending requests and receiving answers between any combination of systems.
 
Messaging is used to reach to all parts of the data center and to user endpoints.  Messaging is fundamental to the ability to launch APIs anywhere.  Systems of engagement are dependent on implementing management decentralization and supporting user empowerment leveraging messaging.   Mission-critical messaging forms the base for all financial systems.  
 
Scale is everything in the era of Clos architecture of the data center and optical transceivers for inside the data center.   Data moves at the speed of light around the network inside the data center so scale is important.  The charter of mission-critical messaging relates to automatically interconnected APIs.  Robotic software is used to install the automated APIs to achieve process managed by orchestration.  
 
Cloud is increasing the need for mission critical decoupled messaging so that apps can interconnect automatically, bringing data to the desired compute node.