About this video
Architecture-as-Code (AaC) is the practice of defining and governing your software architecture using executable, version-controlled code rather than static documentation. It has four core principles:
- Explicit Decisions: Architectural decisions are captured as machine-readable code (YAML, SQL, GraphQL schemas, ADRs), not tribal knowledge or slide decks.
- Version Control: Architecture definitions live in Git alongside your code, with full history, branching, and code review.
- Automated Validation: Architectural rules are enforced by fitness functions—automated tests that run on every commit and block violations before they merge.
- Living Documentation: C4 diagrams and documentation stay synchronized with the actual codebase because they're generated from or validated against the code.
The result is architecture that actively enforces standards rather than passively documenting them. When a developer (or AI agent) violates an architectural boundary, the CI/CD pipeline catches it immediately—not weeks later in an architecture review.