cqrs-and-handlers_skill

Overview

This skill applies production-grade Symfony architecture and controlled execution workflows focused on CQRS and handler design. It helps refine boundaries, introduce minimal safe changes, and run work in validated checkpoints to reduce risk. The goal is clear, auditable decisions and a lightweight follow-up backlog for further improvements.

How this skill works

I inspect current boundaries, coupling points, and existing project patterns to avoid unnecessary wide refactors. I propose the smallest coherent architectural adjustment, then execute the change in discrete checkpoints with validation at each stage. Each checkpoint produces a validation outcome, a short decision record, and noted residual risks with recommended next steps.

When to use it

• Refining architecture and context handling in Symfony projects using CQRS
• Planning and executing medium or complex changes that must be low-risk
• Introducing or reorganizing command/query handlers without disrupting runtime behavior
• When you need auditable decisions and clear rollback/validation points
• Preparing a change that will be delivered incrementally across teams

Best practices

• Default to existing project patterns; only deviate when benefits clearly outweigh cost
• Keep changes minimal and coherent to maintain deployability at each checkpoint
• Record a concise decision log for each architectural step and validation result
• Validate behavior at every checkpoint with unit and integration checks
• Avoid broad, simultaneous refactors; break work into verifiable increments

Example use cases

• Introduce a new query handler and migrate a single consumer to the new interface in one checkpoint
• Split a large command handler into smaller units and validate side effects in staged deployments
• Add explicit context propagation (e.g., tenant or user) into handler pipelines with backward-compatible checks
• Rework handler registration (autowiring/config) for better testability and validate with integration tests
• Plan and execute a safe migration from synchronous handlers to queued message handling incrementally