https://projectreactor.io/ http://rsocket.io/docs/Motivations
- Responsive - The system responds in a timely manner if at all possible.
- Resilient - The system stays responsive in the face of failure.
- Elastic - The system stays responsive under varying workload.
- Message Driven - Reactive Systems rely on asynchronous message-passing to establish a boundary between components that ensures loose coupling, isolation and location transparency