What architecture connects each system directly to every other system?

The architecture that connects each system directly to every other system is known as Point-to-Point. In this configuration, each pair of systems communicates directly, establishing a dedicated communication link. This direct connection allows for straightforward integration, as any system can send and receive messages directly from another system without the need for intermediaries.

Point-to-Point architecture can be beneficial in scenarios where there are only a limited number of systems that need to be integrated, as it can lead to simple and faster interactions. However, as the number of systems increases, this architecture can become complex and difficult to manage. Each new connection requires additional development and maintenance, which can lead to scalability issues over time.

In contrast, architectures like the Enterprise Service Bus are designed to manage communications through a central hub, reducing the complexity that comes with direct connections among multiple systems. The Hub and Spoke architecture uses a central hub to manage interactions among various systems, which streamlines the connectivity but does not involve direct connections between all systems. Service-Oriented Architecture (SOA) uses services to define very specific interfaces and capabilities for different systems, promoting reuse but also maintaining a level of abstraction.