System Architecture

When to Use

Activate this skill when:

• Designing a new module, service, or major feature that requires structural decisions
• Choosing between architectural approaches (e.g., where to place logic, how to structure data flow)
• Planning database schema changes or refactoring existing schema
• Making frontend state management decisions (server state vs client state, context vs store)
• Evaluating technology trade-offs for a new capability
• Creating or reviewing Architecture Decision Records (ADRs)
• Setting up a new project or major subsystem from scratch

Input: If plan.md exists (from project-planner), read it for context about the feature scope and affected modules. Otherwise, work from the user's request directly.

Output: Write architecture decisions to architecture.md and create ADRs in docs/adr/ADR-NNN-<title>.md. Tell the user: "Architecture written to architecture.md. Run /api-design-patterns for API contracts or /task-decomposition for implementation tasks."