SKILL.md
Full Stack Software Engineer
When to Use
- Implement a vertical feature (UI + API + persistence)
- Design or change an API consumed by the frontend
- Fix bugs spanning client and server
- Add auth, validation, pagination, or file upload flows
- Write or extend unit, integration, and critical-path e2e tests
When NOT to Use
- Pipeline, GitOps, or cluster operations →
devopsorplatform-engineer - Terraform, networking, or K8s cluster design →
infrastructure-engineer - Security program, audit evidence, or SOC work →
cybersecurity,compliance-engineer - Deep service architecture RFCs across many teams →
senior-software-engineer - Explicit senior full-stack leadership scope →
senior-fullstack-developer
Related skills
| Need | Skill |
|---|---|
| Senior slice delivery and deeper review bar | senior-fullstack-developer |
| RFCs and cross-service design | senior-software-engineer |
| Deploy and observability plumbing | devops |
| Requirements and acceptance criteria | business-analyst |
| User-facing docs | tech-writer-researcher |
| Front-end-only architecture and a11y | senior-frontend-software-engineer |
| Web sessions, CSRF, CORS, hybrid rendering | web-application-developer |
| Customer ticket repro and escalation | support-engineer |
Core Workflows
1. Vertical feature delivery
- Confirm acceptance criteria and edge cases (empty, error, permissions)
- Define API contract and UI states
- Implement server: validation, authz, persistence, migrations
- Implement client against typed contract
- Test: unit (logic), integration (API), e2e (happy path)
- Add logging/metrics on new paths; feature flag if risky
See references/feature_delivery.md for checklist.
2. API and database
| Concern | Default |
|---|---|
| Validation | Schema at boundary (Zod, Pydantic) |
| Auth | Session or JWT; check authz per resource |
| Queries | Avoid N+1; index for access patterns |
| Mutations | Transactions where needed; idempotency keys for payments-like flows |
| Errors | Stable codes; no internal details to clients |
See references/apianddatabase.md for pagination and migrations.
3. Frontend integration
- Match loading/error/empty states to design
- Prefer server fetch for read-heavy pages when using Next.js App Router
- Client components only for interactivity
- Accessible forms (labels, focus, keyboard)
See references/frontend_integration.md for forms and caching.
4. Testing and PR hygiene
- Lint and typecheck clean
- Tests cover changed behavior, not only happy path
- No secrets in repo; env via configuration
- Small PRs; describe rollout and rollback
See references/testing_debugging.md for test pyramid.
5. Production debugging
- Reproduce with correlation ID or request ID
- Check deploys, flags, and recent config changes
- Trace: logs → metrics → DB slow queries
- Fix with regression test; hotfix or rollback per severity
See references/testing_debugging.md for common failures.
When to load references
- Feature flow →
references/feature_delivery.md - APIs and DB →
references/apianddatabase.md - UI integration →
references/frontend_integration.md - Tests and prod issues →
references/testing_debugging.md