Hack23 Future Architecture Standards Skill

Purpose

Define and enforce architecture documentation standards across the Hack23 organization, using the C4 model for system decomposition, future state planning with ADRs (Architecture Decision Records), and consistent documentation patterns across all repositories.

When to Use

• ✅ Documenting system architecture for new or existing projects
• ✅ Creating Architecture Decision Records (ADRs)
• ✅ Planning future state architecture migrations
• ✅ Reviewing architecture documentation for completeness
• ✅ Generating C4 model diagrams for the CIA platform

Do NOT use for:

• ❌ Code-level documentation (use JavaDoc)
• ❌ Security-specific architecture (use security-documentation skill)
• ❌ Operational runbooks (use aws-cloudwatch-monitoring skill)

C4 Model Requirements

Level 1: System Context

Every Hack23 project must include a system context diagram showing:

• The system under description
• All external actors (users, systems)
• Data flows with protocols and formats

C4Context
    title CIA Platform - System Context

    Person(citizen, "Citizen", "Swedish citizen seeking political transparency")
    Person(analyst, "Political Analyst", "Researches political patterns")

    System(cia, "CIA Platform", "Political intelligence and analysis")

    System_Ext(riksdag, "Riksdagen API", "Swedish Parliament open data")
    System_Ext(val, "Val.se", "Swedish Election Authority")
    System_Ext(worldbank, "World Bank", "Economic indicators")
    System_Ext(esv, "ESV", "Swedish financial data")

    Rel(citizen, cia, "Views political data", "HTTPS")
    Rel(analyst, cia, "Analyzes political trends", "HTTPS")
    Rel(cia, riksdag, "Fetches parliament data", "HTTPS/JSON")
    Rel(cia, val, "Fetches election data", "HTTPS/JSON")
    Rel(cia, worldbank, "Fetches economic data", "HTTPS/JSON")
    Rel(cia, esv, "Fetches financial data", "HTTPS/JSON")

Level 2: Container Diagram

Show major deployable units:

C4Container
    title CIA Platform - Container Diagram

    Container(webapp, "Web Application", "Vaadin/Spring", "Political data dashboards")
    ContainerDb(db, "PostgreSQL", "Database", "Political data store")
    Container(agent, "Data Agent", "Spring Integration", "Data import pipelines")

    Rel(webapp, db, "Reads/Writes", "JDBC/JPA")
    Rel(agent, db, "Writes imported data", "JDBC/JPA")

Level 3: Component Diagram

Required for complex modules showing internal components.

Level 4: Code Diagram

Optional — only for critical/complex algorithms.

Architecture Decision Records (ADRs)

ADR Template

# ADR-{number}: {Title}

## Status
{Proposed | Accepted | Deprecated | Superseded by ADR-xxx}

## Context
{What is the issue? Why do we need to make a decision?}

## Decision
{What is the change that we're proposing and/or doing?}

## Consequences
### Positive
- {Benefit 1}
- {Benefit 2}

### Negative
- {Trade-off 1}
- {Trade-off 2}

### Risks
- {Risk 1 and mitigation}

ADR Naming Convention

• File: docs/adr/ADR-NNNN-short-title.md
• Number: Sequential, zero-padded to 4 digits
• Title: Kebab-case, descriptive

Future State Planning

Documentation Requirements

Each Hack23 project must maintain:

Document	Purpose	Update Frequency
ARCHITECTURE.md	Current state architecture	Every major change
FUTURE_ARCHITECTURE.md	Target state architecture	Quarterly review
SECURITY_ARCHITECTURE.md	Security architecture	Every security change
DATA_MODEL.md	Entity relationship diagrams	Every schema change
FLOWCHART.md	Data processing workflows	When workflows change
MINDMAP.md	Component relationships	Annually

Migration Planning Template

## Current State → Future State

### Phase 1: Foundation (Q1)
- [ ] Milestone 1: Description
- [ ] Milestone 2: Description

### Phase 2: Migration (Q2)
- [ ] Milestone 3: Description

### Phase 3: Optimization (Q3)
- [ ] Milestone 4: Description

### Rollback Plan
- Step 1: {rollback action}
- Step 2: {verification}

Diagram Standards

Tool Chain

• Mermaid — primary diagramming tool (renders in GitHub Markdown)
• PlantUML — alternative for complex UML diagrams
• C4-PlantUML — C4 model diagrams with PlantUML

Diagram Checklist

• Title present and descriptive
• All elements labeled
• Relationships have descriptions and protocols
• Legend included for non-standard notation
• Consistent color scheme across diagrams
• Rendered preview verified in GitHub

Cross-Repository Consistency

Hack23 Organization Standards

All repositories under github.com/Hack23/ must:

1. Use consistent naming — ARCHITECTURE.md, not architecture.md
2. Include C4 Level 1 at minimum in ARCHITECTURE.md
3. Maintain FUTURE_*.md documents for forward planning
4. Link related repos — cross-reference dependent systems
5. Version diagrams — include date or version in diagram titles

ISMS Alignment

Control	Requirement
ISO 27001 A.5.1	Policies for information security (documented)
ISO 27001 A.8.25	Secure development lifecycle documentation
NIST CSF ID.AM-2	Software platform inventory
CIS Control 2	Inventory and control of software assets