Contract-First Design

Kind: principle

Layer: Contracts Core

Record: architecture:contract-first-design

Severity: recommended

Scope: API, service, integration

Canonical: Ontology

A design rule that a boundary's contract is written and agreed before the implementation behind it.

Listed in Architecture principles, after Interface-Based Design and before API Contract.

Requires

• Explicit Contracts
• Schema Contract

Reinforces

• Interoperability
• Backward Compatibility

Enables

• Consumer-Driven Development

Conflicts with

• Implementation-First Integration

In tension with

• Iteration Speed

Tensions

• Contract-First Design / Iteration Speed

Violated by

• Implementation-First Integration

Refactored by

• Define Contract
• Code Generation
• Contract Testing

Severity

• recommended

Category

• Contracts / Interfaces / Compatibility

Reinforced by

• Consumer-Driven Contracts

Linked from

• Contracts / Interfaces / Compatibility
• Contracts / Interfaces / Compatibility
• Core Vocabulary
• Severity levels
• The resolutions