architect-system

System Architecture Designer — Orchestrator

Transforms product specifications into a technical blueprint covering stack, schema, APIs, and deployment. Capability metadata (route triggers, prerequisites, load map, artifact contract) lives in routing.yaml. Methodology and history: references/playbook.md.

Core question: Will this still work at 10x scale with 10x team?

When To Use

• Defined product or feature needing a technical blueprint (stack, schema, API, infra, deployment).
• Major scale shift (10x growth) or migration to new core infrastructure.
• Greenfield, brownfield (extending existing system), or migration (replacing existing).
• Architecture re-run after significant spec change.

When NOT To Use

• Requirements fuzzy → /discover.
• Code-level cleanup → /clean-code.
• Task decomposition from existing architecture → /breakdown-tasks.
• UI/flow mapping → /map-user-flow.
• Existing code has the same operational mechanics duplicated across 2+ callers → /extract-service.

Before Starting

Artifact	Source	Required?
research/product-context.md	research-icp	Recommended — product dims, voice, constraints
docs/forsvn/artifacts/meta/specs/*.md	spec/PRD	Recommended — feature scope
docs/forsvn/artifacts/product/flow/*.md	map-user-flow	Recommended — user types + flows
docs/forsvn/experience/technical.md	(any skill)	Optional — stack history + constraints
.forsvn/index/manifest.json	system	Optional — prior runs + downstream task state

Apply references/_shared/before-starting-check.md. --fast forces single-agent regardless of scope; All 8 Critical Gates fire in every mode.

Pre-Dispatch

Run references/_shared/pre-dispatch-protocol.md. Needed dimensions: spec/PRD reference, scale targets (users / RPS / data), constraints (budget / team skills / latency / compliance), deployment context (greenfield / brownfield / migration). Full read-order + interview prompts: references/procedures/pre-dispatch.md.

Critical Gates — all 8 fire in every mode

Before delivering, the critic-agent verifies ALL of these pass:

• Every tech choice has a rationale (not just "it's popular").
• API endpoints exist for every user-facing feature.
• Database schema covers all entities mentioned in product spec.
• Deployment section includes complete env var list.
• File structure matches chosen framework conventions.
• Auth model covers all user roles and permission levels.
• At least one architectural trade-off is documented with alternatives considered.
• Every external dependency is classified (in-process / local-substitutable / remote-owned / true-external) per references/dependency-classification.md.

Failure → critic identifies which agent must fix it; orchestrator re-dispatches with specific feedback. Revision-loop handling + 2-round limit: references/anti-patterns.md § "Revision loop".

Artifact Contract

• Path: architecture/system-architecture.md (active); prior runs renamed system-architecture.v[N].md.
• Lifecycle: canonical — top-level folder; edited in place by humans + future runs; team's authoritative architecture record.
• Frontmatter: skill, version, date, status, stack (=product), review_surface (=html — the forsvn-preview review module renders the themed preview while decision_state: pending), decision_state, review_tool, reviewed_at, reviewer, lifecycle, produced_by, provenance. v2 schema in references/_shared/artifact-contract-template.md.
• Required sections: 12 sections (§1 Overview → §12 Security Review) + §12a STRIDE + §12b OWASP + §12d false-positive log. §12c LLM/AI Security conditional. Not Included + Open Questions when applicable.
• Consumed by: breakdown-tasks, review-work, clean-code, forsvn, operator.

Full template + section content + version-increment rule: references/report-template.md.

Chain Position

Previous: /discover or /map-user-flow (optional, both sharpen output) | Next: /breakdown-tasks (decomposes into tasks). Cross-stack: reads docs/forsvn/artifacts/meta/sketches/prioritize-*.md.

Re-run triggers: product spec changes significantly, scale requirements change (10x growth), migrating core infrastructure, adding major new integrations.

Dispatch

Multi-agent default (7 agents: stack-selection · infrastructure · schema · api · integration · scaling · critic). Single-agent fallback when mode-resolver downgrades to fast. Full execution layers, dispatch protocol, routing logic, and fallback steps: references/procedures/dispatch-mechanics.md. Per-agent role + file paths: references/agent-manifest.md. Session execution profile (single-vs-multi): inherit per references/_shared/execution-policy.md.

Anti-Patterns

Read references/anti-patterns.md at every doubt — premature microservices, schema without queries, auth-as-afterthought, missing error states, "we'll add monitoring later," over-engineering for scale. Revision-loop handling + when-to-defer-instead-of-architecting also live there.

Durable Rules (protected)

Completion Status

• DONE — full architecture written (stack, schema, API, infra, scaling), critic PASS, open questions listed.
• DONE_WITH_CONCERNS — written with scaling assumptions or stack tradeoffs flagged in Open Questions.
• BLOCKED — requirements contradict (budget vs scale, latency vs cost); needs user trade-off decision.
• NEEDS_CONTEXT — spec, prioritized initiatives, or user-flows missing; recommend /discover, /prioritize, or /map-user-flow first.

Next Step

After delivery: the operator reviews + sets the decision via the forsvn-preview review module (/forsvn:review), decision_state. Approved → dispatch /breakdown-tasks to decompose into tasks. Suggested edits → re-run with feedback. Denied → loop back to /discover or /map-user-flow.

References

• references/procedures/{pre-dispatch, dispatch-mechanics}.md
• references/playbook.md, references/agent-manifest.md, references/anti-patterns.md, references/report-template.md
• references/_shared/{pre-dispatch-protocol, before-starting-check, mode-resolver}.md
• references/pre-dispatch-prompts.md, dependency-classification.md
• Pattern catalogs (agent-consumed): tech-stack-patterns.md, tech-stack-matrix.md, file-structure-patterns.md, database-patterns.md, api-patterns.md, auth-patterns.md, deployment-patterns.md, failure-modes.md, interaction-edge-cases.md, security-patterns.md
• Walkthrough: references/examples/saas-invoicing-walkthrough.md