Architectural pattern

Also known as an architectural style, an architectural pattern is a reusable, named solution to a recurring structural problem in software design, applied at the level of a whole system or major subsystem, rather than to a single class or function, which is the scope of a design pattern.

Architectural patterns describe how the major components of a system are organized and how they communicate, not the fine-grained implementation details within any one component.

An architectural pattern expresses a fundamental structural organization schema for software systems. It provides a set of predefined sub-systems, specifies their responsibilities, and includes rules and guidelines for organizing the relationships between them

– Buschmann et al
1996

Examples of architectural patterns include the following.

• Blackboard
• broker
• Client-server architecture
• cqrs
• Data-oriented architecture
• dependency injection
• Domain-driven design
• Entity Component System (ECS)
• Event-driven architecture
• Event sourcing
• Hexagonal architecture
• Layered architecture
• Message-driven architecture
• Micro frontend
• Microservices
• model-view controller
• Monoliths
• Nanoservices
• onion architecture
• Pipe and filter
• plugin
• Ports and adapters
• Reactive programming
• remote procedure call
• Request-response
• Serverless architecture
• Service-oriented architecture
• Strangler fig pattern
• Vertical-slice architecture

Choosing an architectural pattern is one of the most consequential decisions in software architecture, because it shapes how easy a system is to change, scale, test, and reason about for the lifetime of the system. Unlike a design pattern applied locally to a single class or package, an architectural pattern is difficult and expensive to change once a system is built around it.

See also

• System design

References

• Bushman et al (1996). Pattern-Oriented Software Architecture ("POSA"). — A series of books on software architecture patterns and design patterns. The first volume, known as POSA-1, is regarded as one of the most groundbreaking books on architecture patterns.
• Fowler et al (2002). Patterns of Enterprise Application Architecture ("PoEAA").