<!-- Generated by mstack from Misbah's Build Like This workflow. Regenerate instead of editing. -->

backend-delivery

This skill is part of Misbah Khursheed's Build Like This workflow. Thinking, evidence, and explicit trade-offs come before generated output.

Project identity and sources of truth

The repository where this skill is installed is the host project being built. Build Like This is the method used to build it; mstack only installs and reconciles method resources. Do not assume mstack or Build Like This is the product unless project-owned sources explicitly identify this repository as mstack itself.

Use project-owned docs/, decisions, executable code, and tests as sources of truth. .mstack/templates/ are reference scaffolds to copy and adapt into project-owned documents, not product requirements and not a replacement for docs/.

Purpose

Implement server-owned behavior after product and architecture decisions are defined. Unlike build-feature, this is the backend phase and stops at stable contracts and server behavior ready for frontend integration.

Required inputs

• Approved feature behavior, architecture, actors/permissions, state transitions, API/event contracts, errors, and acceptance criteria.
• Relevant backend modules, schemas/migrations, tests, provider adapters, compatibility, and operational requirements.
• Authorization, privacy, idempotency/concurrency, latency, reliability, rollout, and recovery constraints.

If a missing input would materially change the result, state the gap and obtain or discover it before proceeding. Otherwise label the assumption and continue.

Process

1. Have the backend engineer lead; delegate database, security, and independent contract/test lanes, adding AI review only for AI boundaries.
2. Reconcile the agreed contract with current behavior and update project-owned feature/architecture sources before implementation if decisions changed.
3. Define runtime-validated requests/responses/errors, resource authorization, invariants, transaction boundaries, and compatibility before handlers.
4. Implement domain/application behavior through owning interfaces, then connect persistence and provider adapters with timeouts and bounded recovery.
5. Add structured redacted observability and test success, limits, malformed input, denial, duplicates/concurrency, dependency failure, and recovery.
6. Run focused and package-level type, lint, test, and production-build checks; document configuration, migration order, rollout, and frontend contract handoff.

Output contract

• A narrow backend implementation with stable validated contracts, explicit permissions/errors, and preserved compatibility.
• Unit, integration, contract, security, and recovery evidence proportionate to the changed risks.
• Frontend integration examples plus migration, observability, rollout, recovery, and residual-risk notes.

Guardrails

• Do not place domain rules in HTTP handlers, ORM models, jobs, or provider callbacks.
• Do not let clients enforce server-owned authorization, financial state, or durable invariants.
• Do not change a public contract or applied migration history without a compatible documented path.

Delegation and parallel safety

• Material lifecycle work must delegate at least one bounded specialist lane when subagents are available. Prefer two or more concurrent lanes only for independent evidence gathering, analysis, or non-overlapping file ownership.
• The active lead owns integration and acceptance. Supporting agents do not recursively delegate unless explicitly promoted to lead a named lane.
• Assign distinct outputs and ownership. Serialize shared docs, contracts, schemas, migrations, deployments, external writes, and overlapping file edits.
• When subagents are unavailable, perform the same named specialist passes sequentially and state that constraint instead of implying parallel verification.
• Delegation never grants permission for outreach, consequential external actions, destructive changes, paid resources, or production operations.

End with the evidence gathered, verification performed, and any residual risk or unresolved decision.