Composability

Kind: principle

Layer: Structural Core

Record: architecture:composability

Severity: recommended

Scope: function, component, system

Canonical: Ontology

A design rule that parts share compatible interfaces and carry no hidden side effects, so they can be combined into larger parts.

Listed in Architecture principles, after Modularity and before Composition Over Inheritance.

Requires

• Stable Interfaces
• Low Coupling

Reinforces

• Modularity
• Reusability

Enables

• Pipeline Architecture
• Plugin Architecture

Conflicts with

• Monolithic Procedures

In tension with

• Performance Overhead

Tensions

• Composability / Performance Overhead

Violated by

• Hidden Side Effect
• Implementation-Specific Contracts

Refactored by

• Standardize the Interface
• Extract Module
• Adapter Pattern

Severity

• recommended

Category

• Core Modular Design

Reinforced by

• Decorator Pattern
• Component-Based Architecture
• Pipes and Filters

Linked from

• Principles are typed
• Contracts / Interfaces / Compatibility
• Core Modular Design
• SOLID / Object-Oriented Design
• Structural Patterns
• Streaming / Pipeline / Dataflow Processing
• Plugin / Extensibility / IoC
• Codebase / System Architecture Styles
• Contracts / Interfaces / Compatibility
• Core Modular Design
• Severity levels
• The resolutions