backend-dev-guidelines-v3

name	backend-dev-guidelines-v3
description	Backend Development Guidelines workflow skill. Use this skill when the user needs You are a senior backend engineer operating production-grade services under strict architectural and reliability constraints. Use when routes, controllers, services, repositories, express middleware, or prisma database access and the operator should preserve the upstream workflow, copied support files, and provenance before merging or handing off.
version	0.0.1
category	backend
tags	["backend-dev-guidelines-v3","backend-dev-guidelines","you","are","senior","backend","engineer","operating"]
complexity	advanced
risk	caution
tools	["codex-cli","claude-code","cursor","gemini-cli","opencode"]
source	community
author	sickn33
date_added	2026-04-26
date_updated	2026-05-17

Backend Development Guidelines

Overview

This public intake copy packages plugins/antigravity-bundle-full-stack-developer/skills/backend-dev-guidelines from https://github.com/sickn33/antigravity-awesome-skills into the native Omni Skills editorial shape without hiding its origin.

Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow.

This intake keeps the copied upstream files intact and uses the external_source block in metadata.json plus ORIGIN.md as the provenance anchor for review.

Backend Development Guidelines (Node.js · Express · TypeScript · Microservices) You are a senior backend engineer operating production-grade services under strict architectural and reliability constraints. Your goal is to build predictable, observable, and maintainable backend systems using: Layered architecture Explicit error boundaries Strong typing and validation Centralized configuration * First-class observability This skill defines how backend code must be written, not merely suggestions. ---

Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: 2. Core Architecture Doctrine (Non-Negotiable), 3. Directory Structure (Canonical), 4. Naming Conventions (Strict), 7. Async & Error Handling, 8. Observability & Monitoring, 9. Testing Discipline.

When to Use This Skill

Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request.

• Routes, controllers, services, repositories
• Express middleware
• Prisma database access
• Zod validation
• Sentry error tracking
• Configuration management

Operating Table

Situation	Start here	Why it matters
First-time use	metadata.json	Confirms repository, branch, commit, and imported path through the external_source block before touching the copied workflow
Provenance review	ORIGIN.md	Gives reviewers a plain-language audit trail for the imported source
Workflow execution	resources/architecture-overview.md	Starts with the smallest copied file that materially changes execution
Supporting context	resources/async-and-errors.md	Adds the next most relevant copied source file without loading the entire package
Handoff decision	## Related Skills	Helps the operator switch to a stronger native skill when the task drifts

Workflow

This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow.

1. Confirm the user goal, the scope of the imported workflow, and whether this skill is still the right router for the task.
2. Read the overview and provenance files before loading any copied upstream support files.
3. Load only the references, examples, prompts, or scripts that materially change the outcome for the current request.
4. Execute the upstream workflow while keeping provenance and source boundaries explicit in the working notes.
5. Validate the result against the upstream expectations and the evidence you can point to in the copied files.
6. Escalate or hand off to a related skill when the work moves out of this imported workflow's center of gravity.
7. Before merge or closure, record what was used, what changed, and what the reviewer still needs to verify.

Imported Workflow Notes

Imported: 2. Core Architecture Doctrine (Non-Negotiable)

1. Layered Architecture Is Mandatory

Routes → Controllers → Services → Repositories → Database

• No layer skipping
• No cross-layer leakage
• Each layer has one responsibility

---

2. Routes Only Route

// ❌ NEVER
router.post('/create', async (req, res) => {
  await prisma.user.create(...);
});

// ✅ ALWAYS
router.post('/create', (req, res) =>
  userController.create(req, res)
);

Routes must contain zero business logic.

---

3. Controllers Coordinate, Services Decide

• Controllers:

  • Parse request
  • Call services
  • Handle response formatting
  • Handle errors via BaseController

• Services:

  • Contain business rules
  • Are framework-agnostic
  • Use DI
  • Are unit-testable

---

4. All Controllers Extend BaseController

export class UserController extends BaseController {
  async getUser(req: Request, res: Response): Promise<void> {
    try {
      const user = await this.userService.getById(req.params.id);
      this.handleSuccess(res, user);
    } catch (error) {
      this.handleError(error, res, 'getUser');
    }
  }
}

No raw res.json calls outside BaseController helpers.

---

5. All Errors Go to Sentry

catch (error) {
  Sentry.captureException(error);
  throw error;
}

❌ console.log ❌ silent failures ❌ swallowed errors

---

6. unifiedConfig Is the Only Config Source

// ❌ NEVER
process.env.JWT_SECRET;

// ✅ ALWAYS
import { config } from '@/config/unifiedConfig';
config.auth.jwtSecret;

---

7. Validate All External Input with Zod

• Request bodies
• Query params
• Route params
• Webhook payloads

const schema = z.object({
  email: z.string().email(),
});

const input = schema.parse(req.body);

No validation = bug.

---

Examples

Example 1: Ask for the upstream workflow directly

Use @backend-dev-guidelines-v3 to handle <task>. Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer.

Explanation: This is the safest starting point when the operator needs the imported workflow, but not the entire repository.

Example 2: Ask for a provenance-grounded review

Review @backend-dev-guidelines-v3 against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why.

Explanation: Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection.

Example 3: Narrow the copied support files before execution

Use @backend-dev-guidelines-v3 for <task>. Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding.

Explanation: This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default.

Example 4: Build a reviewer packet

Review @backend-dev-guidelines-v3 using the copied upstream files plus provenance, then summarize any gaps before merge.

Explanation: This is useful when the PR is waiting for human review and you want a repeatable audit packet.

Best Practices

Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution.

• Services receive dependencies via constructor
• No importing repositories directly inside controllers
• Enables mocking and testing
• Prisma client never used directly in controllers
• Repositories:
• Encapsulate queries
• Handle transactions

Imported Operating Notes

Imported: 5. Dependency Injection Rules

• Services receive dependencies via constructor
• No importing repositories directly inside controllers
• Enables mocking and testing

export class UserService {
  constructor(
    private readonly userRepository: UserRepository
  ) {}
}

---

Imported: 6. Prisma & Repository Rules

• Prisma client never used directly in controllers

• Repositories:

  • Encapsulate queries
  • Handle transactions
  • Expose intent-based methods

await userRepository.findActiveUsers();

---

Troubleshooting

Problem: The operator skipped the imported context and answered too generically

Symptoms: The result ignores the upstream workflow in plugins/antigravity-bundle-full-stack-developer/skills/backend-dev-guidelines, fails to mention provenance, or does not use any copied source files at all. Solution: Re-open metadata.json, ORIGIN.md, and the most relevant copied upstream files. Check the external_source block first, then restate the provenance before continuing.

Problem: The imported workflow feels incomplete during review

Symptoms: Reviewers can see the generated SKILL.md, but they cannot quickly tell which references, examples, or scripts matter for the current task. Solution: Point at the exact copied references, examples, scripts, or assets that justify the path you took. If the gap is still real, record it in the PR instead of hiding it.

Problem: The task drifted into a different specialization

Symptoms: The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better. Solution: Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind.

Related Skills

• @azure-search-documents-py-v3 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @browser-automation-v3 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @cc-skill-security-review-v3 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @docker-expert-v3 - Use when the work is better handled by that native specialization after this imported skill establishes context.

Additional Resources

Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding.

Resource family	What it gives the reviewer	Example path
references	copied reference notes, guides, or background material from upstream	references/n/a
examples	worked examples or reusable prompts copied from upstream	examples/n/a
scripts	upstream helper scripts that change execution or validation	scripts/n/a
agents	routing or delegation notes that are genuinely part of the imported package	agents/n/a
assets	supporting assets or schemas copied from the source package	assets/n/a

• architecture-overview.md
• async-and-errors.md
• complete-examples.md
• configuration.md
• database-patterns.md
• middleware-guide.md

Imported Reference Notes

Imported: 1. Backend Feasibility & Risk Index (BFRI)

Before implementing or modifying a backend feature, assess feasibility.

BFRI Dimensions (1–5)

Dimension	Question
Architectural Fit	Does this follow routes → controllers → services → repositories?
Business Logic Complexity	How complex is the domain logic?
Data Risk	Does this affect critical data paths or transactions?
Operational Risk	Does this impact auth, billing, messaging, or infra?
Testability	Can this be reliably unit + integration tested?

Score Formula

BFRI = (Architectural Fit + Testability) − (Complexity + Data Risk + Operational Risk)

Range: -10 → +10

Interpretation

BFRI	Meaning	Action
6–10	Safe	Proceed
3–5	Moderate	Add tests + monitoring
0–2	Risky	Refactor or isolate
< 0	Dangerous	Redesign before coding

---

Imported: 3. Directory Structure (Canonical)

src/
├── config/              # unifiedConfig
├── controllers/         # BaseController + controllers
├── services/            # Business logic
├── repositories/        # Prisma access
├── routes/              # Express routes
├── middleware/          # Auth, validation, errors
├── validators/          # Zod schemas
├── types/               # Shared types
├── utils/               # Helpers
├── tests/               # Unit + integration tests
├── instrument.ts        # Sentry (FIRST IMPORT)
├── app.ts               # Express app
└── server.ts            # HTTP server

---

Imported: 4. Naming Conventions (Strict)

Layer	Convention
Controller	PascalCaseController.ts
Service	camelCaseService.ts
Repository	PascalCaseRepository.ts
Routes	camelCaseRoutes.ts
Validators	camelCase.schema.ts

---

Imported: 7. Async & Error Handling

asyncErrorWrapper Required

All async route handlers must be wrapped.

router.get(
  '/users',
  asyncErrorWrapper((req, res) =>
    controller.list(req, res)
  )
);

No unhandled promise rejections.

---

Imported: 8. Observability & Monitoring

Required

• Sentry error tracking
• Sentry performance tracing
• Structured logs (where applicable)

Every critical path must be observable.

---

Imported: 9. Testing Discipline

Required Tests

• Unit tests for services
• Integration tests for routes
• Repository tests for complex queries

describe('UserService', () => {
  it('creates a user', async () => {
    expect(user).toBeDefined();
  });
});

No tests → no merge.

---

Imported: 10. Anti-Patterns (Immediate Rejection)

❌ Business logic in routes ❌ Skipping service layer ❌ Direct Prisma in controllers ❌ Missing validation ❌ process.env usage ❌ console.log instead of Sentry ❌ Untested business logic

---

Imported: 11. Integration With Other Skills

• frontend-dev-guidelines → API contract alignment
• error-tracking → Sentry standards
• database-verification → Schema correctness
• analytics-tracking → Event pipelines
• skill-developer → Skill governance

---

Imported: 12. Operator Validation Checklist

Before finalizing backend work:

• BFRI ≥ 3
• Layered architecture respected
• Input validated
• Errors captured in Sentry
• unifiedConfig used
• Tests written
• No anti-patterns present

---

Imported: 13. Skill Status

Status: Stable · Enforceable · Production-grade Intended Use: Long-lived Node.js microservices with real traffic and real risk

When to Use

This skill is applicable to execute the workflow or actions described in the overview.

Imported: Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.