SKILL.md
Domain-Driven Design
Use this skill when
- You need to model a complex business domain with explicit boundaries.
- You want to decide whether full DDD is worth the added complexity.
- You need to connect strategic design decisions to implementation patterns.
- You are planning CQRS, event sourcing, sagas, or projections from domain needs.
Do not use this skill when
- The problem is simple CRUD with low business complexity.
- You only need localized bug fixes.
- There is no access to domain knowledge and no proxy product expert.
Instructions
- Run a viability check before committing to full DDD.
- Produce strategic artifacts first: subdomains, bounded contexts, language glossary.
- Route to specialized skills based on current task.
- Define success criteria and evidence for each stage.
Viability check
Use full DDD only when at least two of these are true:
- Business rules are complex or fast-changing.
- Multiple teams are causing model collisions.
- Integration contracts are unstable.
- Auditability and explicit invariants are critical.
Routing map
- Strategic model and boundaries:
@ddd-strategic-design - Cross-context integrations and translation:
@ddd-context-mapping - Tactical code modeling:
@ddd-tactical-patterns - Read/write separation:
@cqrs-implementation - Event history as source of truth:
@event-sourcing-architectand@event-store-design - Long-running workflows:
@saga-orchestration - Read models:
@projection-patterns - Decision log:
@architecture-decision-records
If templates are needed, open references/ddd-deliverables.md.
Output requirements
Always return:
- Scope and assumptions
- Current stage (strategic, tactical, or evented)
- Explicit artifacts produced
- Open risks and next step recommendation
Examples
Use @domain-driven-design to assess if this billing platform should adopt full DDD.
Then route to the right next skill and list artifacts we must produce this week.Limitations
- This skill does not replace direct workshops with domain experts.
- It does not provide framework-specific code generation.
- It should not be used as a justification to over-engineer simple systems.