Lesson 14: Architectural Decision Records (ADRs) – Documenting Design Decisions Effectively
Making architectural decisions is just the beginning. Documenting them ensures clarity, alignment, and continuity across teams. This lesson introduces Architectural Decision Records (ADRs) as a lightweight and powerful practice for capturing and communicating key technical decisions.
1. What Are Architectural Decision Records?
Explanation: ADRs are short text documents that describe important architectural decisions made during the project and their context and consequences.
Example Use Case: Choosing between SQL and NoSQL for a user service and documenting the rationale and trade-offs.
2. Benefits of Using ADRs
- Preserves decision history with context
- Aligns teams and avoids repeated discussions
- Improves onboarding and future audits
3. ADR Structure
Typical Sections:
- Title: Concise summary
- Status: Proposed / Accepted / Deprecated
- Context: Background and problem
- Decision: What was decided
- Consequences: Impact of this decision
4. Tools and Storage
- Markdown files stored in
/docs/adror/architecture/decisionsfolder in Git - Popular tools: adr-tools
5. Best Practices for Effective ADRs
- Write ADRs as soon as a decision is made
- Keep them concise and focused
- Link them to related PRs, issues, or documentation
- Review and deprecate outdated ADRs regularly
Conclusion
ADRs are a lightweight but high-impact practice that brings discipline, traceability, and clarity to software architecture. They help teams evolve systems with confidence, continuity, and shared understanding.