ADR Approaches: Comparison and Recommendations⚓︎

Overview⚓︎

This document compares different approaches to documenting architectural decisions and provides recommendations based on project size, team structure, and organizational needs.

Quick Comparison Table⚓︎

Approach	Formality	Complexity	Time to Create	Best For	Tools Required
Y-Statements	Low	Very Low	5-15 min	Quick decisions, small teams	None
MADR	Medium	Low-Medium	30-60 min	Most projects	Markdown editor
AWS ADR	Medium-High	Medium	1-2 hours	Enterprise teams	Markdown editor
log4brains	Medium	Medium	30-60 min	Teams wanting website	log4brains CLI
Prefect PINs	Medium-High	Medium-High	Days-Weeks	Open source proposals	GitHub
Ethereum EIPs	Very High	Very High	Weeks-Months	Protocol/standards	GitHub, expertise

Detailed Comparison⚓︎

Format and Structure⚓︎

Aspect	Y-Statements	MADR	AWS ADR	log4brains	Prefect PINs	Ethereum EIPs
File Format	Any (text/markdown)	Markdown	Markdown	Markdown (MADR default)	Markdown/GitHub	Markdown
Template	Single sentence	Multiple sections	Multiple sections	Customizable	Issue template	Rigorous specification
Sections	6 components	5-10 sections	3-5 core sections	Based on template	Varies	10+ sections
Length	1 sentence	1-3 pages	1-2 pages	1-3 pages	2-10 pages	5-50 pages
Metadata	Minimal	Optional YAML	Optional	Auto-extracted	GitHub metadata	Extensive header

Process and Workflow⚓︎

Aspect	Y-Statements	MADR	AWS ADR	log4brains	Prefect PINs	Ethereum EIPs
Creation Time	5-15 min	30-60 min	1-2 hours	30-60 min	Days-Weeks	Weeks-Months
Review Process	Informal	PR review	Team meeting	PR review	Public discussion	Multi-stage review
Approval	Team lead	Team consensus	Team meeting	Merge to main	Maintainers	Community consensus
Revision	Easy	Medium	Medium	Medium	Common	Expected
Status Tracking	Minimal	Explicit states	Explicit states	4 states	GitHub labels	9+ states

Tooling and Integration⚓︎

Aspect	Y-Statements	MADR	AWS ADR	log4brains	Prefect PINs	Ethereum EIPs
Special Tools	None	None	None	log4brains CLI	GitHub	GitHub + Jekyll
Version Control	Any	Git	Git	Git	Git (GitHub)	Git (GitHub)
Documentation Site	Manual	Manual	Manual	Auto-generated	GitHub issues	GitHub Pages
Search	grep/text search	grep/text search	grep/text search	Built-in	GitHub search	Site search
Templates	One format	4 variants	AWS templates	Customizable	Project-specific	EIP-1 template

Team and Project Fit⚓︎

Aspect	Y-Statements	MADR	AWS ADR	log4brains	Prefect PINs	Ethereum EIPs
Team Size	1-5	1-20	5-50	3-50	5-100+	Ecosystem-wide
Project Size	Small-Medium	Any	Medium-Large	Medium-Large	Large	Very Large
Formality	Informal	Semi-formal	Formal	Semi-formal	Formal	Very Formal
Learning Curve	Very Low	Low	Medium	Medium	Medium-High	High
Maintenance	Very Low	Low	Medium	Medium	High	Very High

Recommendations by Project Size⚓︎

Tiny Projects (1-2 developers, < 6 months)⚓︎

Recommended: Y-Statements or simple notes in README

Rationale:

Minimal overhead
Quick to create
Low maintenance
Easy to evolve

Implementation:

## Architecture Decisions

### Use SQLite for storage (2024-01-15)

In the context of local data storage, facing the need for simple persistence, we decided for SQLite and against PostgreSQL, to achieve zero-configuration deployment, accepting that we're limited to single-server deployment.

Pros:

No process overhead
Captures essentials
Fast iteration

Cons:

May lack detail for complex decisions
Less discoverable
Harder to maintain as project grows

Small Projects (2-5 developers, 6 months - 2 years)⚓︎

Recommended: MADR (Minimal variant)

Rationale:

Lightweight but structured
Scales with project growth
No special tools needed
Industry standard

Implementation:

project/
├── docs/
│   └── adr/
│       ├── 0001-record-architecture-decisions.md
│       ├── 0002-use-pytest-for-testing.md
│       └── 0003-implement-rest-api.md

Template: Use MADR minimal template

Process:

Developer creates ADR in PR
Team reviews in code review
Merge to main

Pros:

Low overhead
Structured format
Room to grow
Familiar workflow

Cons:

Requires discipline
No automated tooling
Manual indexing

Medium Projects (5-15 developers, 2-5 years)⚓︎

Recommended: MADR (Full variant) or AWS ADR Guide

Rationale:

Need more structure
Multiple team members
Longer timeline needs documentation
More stakeholders

Implementation:

project/
├── docs/
│   ├── adr/
│   │   ├── README.md (index)
│   │   ├── backend/
│   │   │   ├── 0001-database-selection.md
│   │   │   └── 0002-api-framework.md
│   │   └── frontend/
│   │       ├── 0001-react-vs-vue.md
│   │       └── 0002-state-management.md

Template: Full MADR or AWS ADR template

Process:

ADR required for architectural decisions
Team review meeting for significant decisions
PR review for all ADRs
Integration with documentation site (MkDocs, Docusaurus)

Considerations:

Categorization: Organize by component/layer
Index: Maintain README with list and status
Integration: Add to CI/CD to validate format
Reviews: Make ADRs part of architecture review

Pros:

Comprehensive documentation
Organized structure
Supports growth
Team alignment

Cons:

More time investment
Needs enforcement
Requires maintenance

Large Projects (15-50 developers, 5+ years)⚓︎

Recommended: log4brains or MADR + documentation site

Rationale:

Many stakeholders
Need searchability
Long-term maintenance
Onboarding needs

Implementation Option 1: log4brains

# Initialize
npx log4brains init

# Create ADR
npx log4brains adr new

# Preview
npx log4brains preview

# Build site
npx log4brains build

# Deploy to GitHub Pages

Implementation Option 2: MADR + MkDocs

project/
├── docs/
│   ├── adr/
│   │   ├── index.md
│   │   ├── 0001-*.md
│   │   └── ...
│   └── mkdocs.yml

Process:

ADR template in repo
Automated checks for format
Required reviews by architects
Automatic site generation
Published to internal/external site
Regular audits of ADR status

Considerations:

Tooling: Invest in automation
Governance: Clear ownership and process
Search: Make ADRs easily discoverable
Metrics: Track ADR coverage
Integration: Link from code, docs, issues

Pros:

Excellent searchability
Professional presentation
Supports large teams
Great for onboarding
Historical record

Cons:

Setup overhead
Tool dependency
Requires maintenance
May need dedicated owner

Very Large Projects / Multi-Team (50+ developers)⚓︎

Recommended: AWS ADR Guide approach + centralized tooling

Rationale:

Multiple teams need coordination
Consistent format critical
Enterprise governance
Audit and compliance needs

Implementation:

organization/
├── adr-templates/
│   ├── standard-adr.md
│   ├── security-adr.md
│   └── data-adr.md
├── projects/
│   ├── project-a/
│   │   └── docs/adr/
│   ├── project-b/
│   │   └── docs/adr/

Infrastructure:

Central repository: ADR templates and guidelines
Automated validation: CI/CD checks for format compliance
Search platform: Searchable across all projects
Review board: Architectural review for major decisions
Training: Onboarding for new team members

Process:

Template selection based on decision type
Draft creation by proposer
Stakeholder consultation
Review by architecture board
Team consensus
Final approval and publication
Implementation tracking

Governance:

Ownership: Clear DRI (Directly Responsible Individual)
States: Strict status tracking
Impact analysis: Required for breaking changes
Compliance: Link to regulations/standards
Audit trail: Complete history

Pros:

Enterprise-grade
Consistent across teams
Supports compliance
Clear governance
Excellent traceability

Cons:

High overhead
Complex process
May slow decisions
Requires dedicated resources

Recommendations by Project Type⚓︎

Open Source Projects⚓︎

Recommended: Prefect PINs approach or MADR with public docs

Rationale:

Community involvement
Transparent decision making
Educational value
Build trust

Implementation:

project/
├── docs/
│   ├── adr/
│   │   └── *.md (published to docs site)
├── .github/
│   ├── ISSUE_TEMPLATE/
│   │   └── pin.md

Process:

Community member opens issue/PR with proposal
Discussion in GitHub
Maintainers provide feedback
Revision based on input
Decision by maintainers
Implementation
Documentation in ADR

Considerations:

Accessibility: Make ADRs easy to find
Welcoming: Encourage community proposals
Transparent: Document rationale clearly
Responsive: Timely feedback on proposals

Examples: Prefect, Structurizr Python, Arachne

Internal Enterprise Applications⚓︎

Recommended: AWS ADR Guide or MADR (Full)

Rationale:

Clear governance needed
Compliance requirements
Audit trail
Team turnover

Focus:

Security: Security considerations section
Compliance: Regulatory requirements
Risk: Risk assessment
Cost: TCO analysis

Startups / Fast-Moving Teams⚓︎

Recommended: Y-Statements or MADR (Minimal)

Rationale:

Speed is critical
Rapid iteration
Frequent changes
Small team

Approach:

Start with Y-Statements
Upgrade to MADR when needed
Only document significant decisions
Keep it lightweight

Red Flags to Watch:

Team growing → need more structure
Decisions being revisited → need documentation
Onboarding taking too long → need context

Protocol / Standards Development⚓︎

Recommended: Ethereum EIPs approach

Rationale:

Multiple implementations
High stakes
Security critical
Long-term impact

Requirements:

Rigorous specification
Test cases
Reference implementation
Security analysis
Multi-stage review
Community consensus

Examples: Ethereum, Bitcoin, IETF RFCs

Hybrid Approaches⚓︎

Start Lightweight, Scale Up⚓︎

Path:

Phase 1 (0-6 months): Y-Statements in README
Phase 2 (6-18 months): MADR minimal in docs/adr/
Phase 3 (18-36 months): Full MADR + documentation site
Phase 4 (36+ months): log4brains or custom tooling

Trigger Points:

Team size doubles → increase formality
Decision being re-litigated → need documentation
Onboarding takes > 1 month → need better docs
Compliance requirements → add rigor

Multi-Tier System⚓︎

For large organizations with varied needs:

Tier 1: Y-Statements

Minor decisions
Component-level choices
Quick iterations

Tier 2: MADR

Feature-level decisions
Moderate impact
Team consensus needed

Tier 3: Full ADR

Architectural decisions
Multi-team impact
Long-term consequences

Tier 4: RFC/PIN

Organization-wide changes
Breaking changes
Standards and patterns

Selection Decision Tree⚓︎

Start: Need to document a decision?
│
├─ Is it trivial/reversible? → No documentation needed
│
├─ Small team (< 5) + fast iteration?
│  └─ → Y-Statements
│
├─ Open source + community input?
│  └─ → PIN-style proposal
│
├─ Protocol/standard development?
│  └─ → EIP-style rigorous process
│
├─ Need searchable website?
│  └─ → log4brains
│
├─ Enterprise/compliance needs?
│  └─ → AWS ADR Guide
│
└─ Most other cases?
   └─ → MADR (start minimal, grow as needed)

Common Pitfalls to Avoid⚓︎

1. Too Much Process Too Soon⚓︎

Symptom: Team resists creating ADRs

Fix: Start lighter, add structure as needed

2. Too Little Structure⚓︎

Symptom: ADRs inconsistent, hard to find, missing context

Fix: Adopt standard template, even if minimal

3. Writing Novels⚓︎

Symptom: ADRs take days to write, no one reads them

Fix: Focus on context, decision, consequences. Details can be links.

4. Set It and Forget It⚓︎

Symptom: ADRs out of date, status unclear

Fix: Review quarterly, update status, mark superseded

5. No Enforcement⚓︎

Symptom: Some decisions documented, others not

Fix: Make ADRs part of definition of done, review in retros

6. Wrong Scope⚓︎

Symptom: ADRs for trivial decisions OR missing major ones

Fix: Define what warrants an ADR (architectural significance)

Success Metrics⚓︎

Track these to measure ADR effectiveness:

Coverage: % of architectural decisions documented
Findability: Time to find relevant ADR
Usage: ADRs referenced in PRs, discussions
Onboarding: Time to onboard reduced
Re-litigation: Fewer debates about settled decisions
Compliance: Audit trail completeness

Migration Strategies⚓︎

From No ADRs to ADRs⚓︎

Start with ADR-0001: “Record architecture decisions”
Document next decision: Practice the process
Backfill incrementally: Document existing major decisions as time allows
Make it habit: Add to PR template checklist

From Y-Statements to MADR⚓︎

Choose template: MADR minimal to start
Convert existing: Expand Y-Statements to full ADRs
Update process: Train team on new format
Parallel run: Accept both for transition period

From MADR to log4brains⚓︎

Install log4brains: npx log4brains init
Migrate files: Copy ADRs to log4brains directory
Update metadata: Ensure proper front matter
Generate site: npx log4brains build
Deploy: Publish to GitHub Pages or hosting

Summary Recommendations⚓︎

Your Situation	Recommended Approach	Why
Solo developer	Y-Statements or notes	Minimal overhead, maximum flexibility
Small team (2-5)	MADR Minimal	Lightweight structure, room to grow
Growing team (5-15)	MADR Full	Comprehensive, organized, scalable
Large team (15-50)	log4brains or MADR + site	Searchable, professional, team-friendly
Enterprise (50+)	AWS ADR + governance	Process, compliance, consistency
Open source	MADR + public docs	Transparent, accessible, community-friendly
Need community input	PIN-style proposals	Collaborative, inclusive, transparent
Protocol development	EIP-style rigorous	Specification-grade, multi-implementation
Fast startup	Y-Statements	Speed over process
Regulated industry	AWS ADR + extras	Compliance, audit trail, formality

Next Steps⚓︎

Choose your starting point based on recommendations above
Create ADR-0001 to establish the practice
Select a template and customize if needed
Document your next decision to practice
Review in 3 months and adjust as needed
Scale up as team and project grow

Remember: The best ADR system is the one your team actually uses. Start simple, iterate, and grow your practice over time.