--- name: cqrs-implementation description: "Implement Command Query Responsibility Segregation for scalable architectures. Use when separating read and write models, optimizing query performance, or building event-sourced systems." risk: unknown source: community date_added: "2026-02-27" --- # CQRS Implementation Comprehensive guide to implementing CQRS (Command Query Responsibility Segregation) patterns. ## Use this skill when - Separating read and write concerns - Scaling reads independently from writes - Building event-sourced systems - Optimizing complex query scenarios - Different read/write data models are needed - High-performance reporting is required ## Do not use this skill when - The domain is simple and CRUD is sufficient - You cannot operate separate read/write models - Strong immediate consistency is required everywhere ## Instructions - Identify read/write workloads and consistency needs. - Define command and query models with clear boundaries. - Implement read model projections and synchronization. - Validate performance, recovery, and failure modes. - If detailed patterns are required, open `resources/implementation-playbook.md`. ## Resources - `resources/implementation-playbook.md` for detailed CQRS patterns and templates. ## Limitations - Use this skill only when the task clearly matches the scope described above. - Do not treat the output as a substitute for environment-specific validation, testing, or expert review. - Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.