---
description: Decompose monolith into bounded contexts using DDD principles
triggers:
  - manual
  - archetype:microservices
agents:
  - domain-decomposer
  - architect
---

# Domain Decomposition Workflow

Break down a domain into bounded contexts for microservices.

## Prerequisites
- [ ] Business domain documentation
- [ ] Existing codebase (if migrating)
- [ ] Stakeholder access for clarification

## Phase 1: Domain Discovery

### Step 1.1: Gather Domain Knowledge
```yaml
agent: domain-decomposer
action: analyze
inputs:
  - business_requirements
  - existing_codebase
outputs:
  - domain_terms_glossary
  - business_capabilities_map
```

### Step 1.2: Identify Core Domains
```yaml
agent: domain-decomposer
action: categorize
criteria:
  - core: Competitive advantage
  - supporting: Necessary but not differentiating
  - generic: Commodity, can buy
```

## Phase 2: Context Mapping

### Step 2.1: Draw Bounded Contexts
```yaml
agent: domain-decomposer
action: draw_contexts
patterns:
  - Shared Kernel
  - Customer-Supplier
  - Conformist
  - Anti-Corruption Layer
  - Open Host Service
  - Published Language
```

### Step 2.2: Define Context Relationships
```yaml
agent: architect
action: define_relationships
artifacts:
  - context_map_diagram
  - integration_contracts
```

## Phase 3: Aggregate Design

### Step 3.1: Identify Aggregates
```yaml
agent: domain-decomposer
action: identify_aggregates
rules:
  - Single transaction boundary
  - Consistency boundary
  - Minimal aggregate size
```

### Step 3.2: Define Aggregate Roots
```yaml
agent: domain-decomposer
action: define_roots
outputs:
  - aggregate_specifications
  - invariant_rules
```

## Phase 4: Service Boundaries

### Step 4.1: Map Contexts to Services
```yaml
agent: architect
action: map_services
considerations:
  - Team ownership
  - Deployment independence
  - Data ownership
  - Communication patterns
```

### Step 4.2: Define APIs
```yaml
agent: architect
action: define_apis
style: contract-first
artifacts:
  - openapi_specs
  - async_api_specs
```

## Outputs
- [ ] Domain glossary
- [ ] Context map diagram
- [ ] Aggregate specifications
- [ ] Service boundary definitions
- [ ] API contracts

## Quality Gates
- All contexts have clear ownership
- No cyclic dependencies between contexts
- Aggregates are transaction-consistent
- APIs follow organization standards