Directory Structure

backend/
├── plop-templates/         # Scaffolding for new code artifacts
│   ├── controller.hbs      # Template for Controllers
│   ├── repository.hbs      # Template for Repositories
│   ├── service.hbs         # Template for Services
│   └── module-base/        # Base files for a new module
│       ├── container.ts.hbs
│       ├── index.ts.hbs
│       └── types.ts.hbs
├── src/                    # Main TypeScript source
│   ├── bootstrap/          # Module loader and application startup
│   │   └── loadModules.ts  # Dynamically imports and registers modules
│   ├── config/             # Environment & integration configs
│   │   ├── ai.ts           # AI / GenAI credentials and setup
│   │   ├── app.ts          # Express app configuration (CORS, bodyParser)
│   │   ├── db.ts           # MongoDB connection pool and retry logic
│   │   ├── index.ts        # Aggregates all config exports
│   │   ├── sentry.ts       # Sentry initialization and instrumentation
│   │   ├── smtp.ts         # Email SMTP transporter settings
│   │   └── storage.ts      # Integration with cloud storage (e.g., GCS/S3)
│   ├── container.ts        # InversifyJS DI container setup
│   ├── index.ts            # Application entry point (bootstrapping)
│   ├── instrument.ts       # Sentry instrumentation hooks
│   ├── inversify-adapter.ts# Adapter to integrate Inversify with routing-controllers
│   ├── modules/            # Domain modules, each with controllers/services/repos
│   │   ├── anomalies/      # User and course anomaly detection logic
│   │   ├── auth/           # Authentication and user management
│   │   ├── courses/        # Course and content management
│   │   ├── genAI/          # Generative AI integrations (e.g., question generation)
│   │   ├── notifications/  # Email, invites, and in-app notifications
│   │   ├── quizzes/        # Quiz engine: questions, attempts, grading
│   │   ├── settings/       # Proctoring and custom user/course settings
│   │   └── users/          # Enrollment, progress tracking, watch-time metrics
│   ├── shared/             # Reusable utilities and cross-cutting code
│   │   ├── classes/        # Base classes (e.g., BaseService, BaseRepository)
│   │   ├── constants/      # App-wide constants (status codes, roles)
│   │   ├── database/       # MongoDB client and connection helpers
│   │   ├── functions/      # Small utility functions (OpenAPI generation, auth checks)
│   │   ├── interfaces/     # TypeScript interfaces and DTO definitions
│   │   └── middleware/     # Express middleware (logging, error handling)
│   ├── types.ts            # Global symbols and types for DI bindings
│   └── utils/              # Miscellaneous helper functions
│       ├── env.ts          # Environment variable loader + validation
│       ├── index.ts        # Re-export of utility functions
│       ├── logDetails.ts   # Prints startup route summary and config
│       └── to-bool.ts      # Safe boolean parsing from strings
├── .env                    # Local environment variables (gitignored)
├── .example.env            # Sample `.env` with required keys
├── Dockerfile              # Docker image for single-service deployment
├── Dockerfile-all          # Docker image bundling all modules
├── firebase.json           # Firebase project and auth config
├── package.json            # NPM scripts and dependency list
├── plopfile.cjs            # Plop generator configuration
├── tsconfig.json           # TypeScript compiler settings
├── typedoc.json            # API documentation config
├── vite.config.ts          # (Optional) Frontend build config
└── README.md               # High-level project overview

Why this structure?

• Modularity: Each domain (modules/) is isolated for clear ownership and test boundaries.
• Scaffold Consistency: plop-templates/ ensure new features follow a standard pattern (Controllers → Services → Repositories).
• Separation of Concerns: Config, bootstrap, DI setup, and shared utilities each live in their own folders to reduce coupling.