name: backend_core
router_kit: FullStackKit
description: Node.js/TypeScript core principles, project structure, and TypeScript strict mode rules.
metadata:
skillport:
category: development
tags: [accessibility, api integration, backend, backend core, browser apis, client-side, components, css3, debugging, deployment, frameworks, frontend, fullstack, html5, javascript, libraries, node.js, npm, performance optimization, responsive design, seo, state management, testing, typescript, ui/ux, web development] - backend-database

🔧 Backend Core

Node.js/TypeScript core principles and project structure.

📋 1. Scope

⚙️ 2. TypeScript Strict Mode

{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "noImplicitReturns": true
  }
}

any Forbidden

// ❌ WRONG
function process(data: any) { }

// ✅ RIGHT
function process(data: DataPayload) { }

// Use unknown for unknown types
function parse(input: unknown) { }

📁 3. Project Structure (Feature-First)

src/
├── modules/
│   ├── auth/
│   │   ├── auth.controller.ts
│   │   ├── auth.service.ts
│   │   ├── auth.repository.ts
│   │   └── auth.dto.ts
│   └── users/
├── shared/
│   ├── middleware/
│   ├── guards/
│   └── utils/
├── infrastructure/
│   ├── database/
│   ├── cache/
│   └── logger/
├── config/
└── main.ts

🔐 4. Environment Variables

import { z } from 'zod';

const envSchema = z.object({
  NODE_ENV: z.enum(['development', 'production', 'test']),
  PORT: z.string().transform(Number),
  DATABASE_URL: z.string().url(),
  JWT_SECRET: z.string().min(32),
});

export const env = envSchema.parse(process.env);

🔗 Related Skills

• backend-api - REST/GraphQL design
• backend-database - DB patterns, caching

• backend-database - DB patterns, caching

Backend Core v1.2 - Verified

🔄 Workflow

Source: Node.js Best Practices - Project Structure

Phase 1: Foundation (Structure)

• [ ] Components: Separate folders by component (components/user, components/order), not by technical role (controllers, models).
• [ ] Config: Type-safe environment variables using dotenv and envalid (or Zod).
• [ ] Entry: Separate app into app.ts (setup) and server.ts (listen).

Phase 2: Core Utilities

• [ ] Logger: Install winston or pino instead of console.log.
• [ ] Async Wrapper: Use global handler or wrapper to catch Promise rejections.
• [ ] Linter: Connect ESLint and Prettier settings to CI pipeline.

Phase 3: Hardening

• [ ] Graceful Shutdown: Listen for SIGTERM/SIGINT signals and close connections gently.
• [ ] Health Check: Add /health endpoint.

Checkpoints