🧱 Mastering NestJS – A Comprehensive Hands-on Guide

Welcome to the Mastering NestJS course repository. This course covers everything from the basics of NestJS and its core concepts to advanced integrations like database ORMs, authentication, and real-world project setups.

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📚 Course Modules Overview

📆 Course Schedule

Module	Title	Topics Covered
00	Introduction	Why NestJS, Architecture, Decorators, Integrations
01	Controllers & Services	NestJS building blocks, CRUD APIs, Task module
02	Validation & Pipes	ValidationPipe, DTOs, error handling
03	Exception Filters & Middleware	Filters, Middleware, Guards, Interceptors, Custom Decorators
04	Demo App with All Concepts	Student CRUD APIs, in-memory DB, Swagger, Modular Code
05	Persistence with TypeORM	PostgreSQL setup with Docker, Entities, Repositories
06	Other ORMs and Migrations	Prisma, Sequelize, Mongoose overview
07	Real APIs with Prisma/Mongoose/Sequelize	Food Delivery APIs using various ORMs
08	Authentication & Authorization	Cookie, Session, JWT-based auth, Guards, Passport.js
09	Database Relationships	One-to-Many, Many-to-Many with TypeORM

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🚀 Advanced Topics

Module	Title	Topics Covered
10	NestJS Testing	Unit testing services, controllers, e2e tests using @nestjs/testing, mocking dependencies
11	NestJS Microservices	Message-based architecture, TCP transport, Redis/NATS brokers, request-response, pub/sub patterns
12	NestJS Microservices Demo	Real-world microservice setup, producer/consumer model, distributed task runner
13	NestJS with GraphQL	Introduction to GraphQL, code-first and schema-first, resolvers, queries, mutations, subscriptions
14	NestJS with External Interfaces	Calling third-party APIs, Axios, SOAP, REST integrations, retry strategies, circuit breakers
15	NestJS in a Monorepo	Managing multiple apps/libs with Turborepo, PNPM workspaces, shared modules, CI/CD setup
16	NestJS Advanced Concepts	Reflection, metadata, custom modules, dynamic modules, lifecycle hooks, context-based providers

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📦 00 - Introduction to NestJS

• Why choose NestJS over Express?
• Understanding NestJS architecture (IOC, DI, Decorators)
• Getting started with TypeScript
• Exploring NestJS integrations

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🧱 01 - Controllers and Services (Building Blocks)

• Installing Node.js and Yarn
• Setting up the NestJS CLI
• (Optional) Setting up VSCode + Extensions
• Creating the project with CLI
• Understanding Modules, Controllers, and Services
• Implementing a Tasks Module:
  • Tasks Controller
  • Tasks Service
  • Task Model & DTOs
• CRUD APIs for Tasks
• Task Filtering and Searching

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🔍 02 - Validation and Pipes

• Using ValidationPipe for CreateTask DTO
• Handling Errors (e.g., deleting non-existing tasks)
• Updating Task Status with Validation
• Challenge: Validate Task Filtering/Search Inputs

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⚙️ 03 - Exception Filters, Middleware, and Core Concepts

• Full CRUD API with Tasks
• Deep dive into:
  • Controllers / Providers / Modules
  • Middleware (creating, applying, excluding routes)
  • Exception Filters
  • Pipes and Guards
  • Interceptors
  • Custom Decorators

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🚀 04 - Applying All Learnings in a Demo App

• Build Student Management APIs
• Use In-Memory DB for simplicity
• Full CRUD with Swagger Specs
• DTO-based payload validation
• Token-based Mock Auth APIs
• Apply Guards, Middleware, and Exception Filters
• Understand DAO & Service Layers
• Real-world Code Structure
• API Testing with Swagger and REST Clients
• Modularization and DI framework exploration

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🗄️ 05 - Data Store with TypeORM

• Intro to Persistence Layer
• Setting up PostgreSQL with Docker
• Using pgAdmin to manage DB
• Intro to TypeORM:
  • Connecting to DB
  • Task Entity & Repository
  • Active Record vs Data Mapper
• CRUD Operations with TypeORM
• Challenge Exercises with Solutions

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🔁 06 - Exploring Other ORMs and Migrations

• Brief Introduction to:
  • Prisma
  • Sequelize
  • Mongoose
  • TypeORM
• Compare approaches and syntax

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🧬 07 - Real-World API with Prisma / Mongoose / Sequelize

• Building Food Delivery APIs using:
  • Prisma with Migrations
  • MongoDB + Mongoose
  • Sequelize for SQL databases
• Prisma Schema & Client API
• Modular Services and Controllers with ORM

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🔐 08 - Authentication & Authorization in NestJS

• Types of Auth:
  • Cookies
  • Sessions
  • JWT (Token-based)
• Setup AuthModule
• Create User Entity + Repository
• Signup Flow:
  • Validation
  • Password Strength
  • Conflict/Error Handling
  • Password Hashing with Bcrypt
• Sign In:
  • Implementing Passport.js + JWT Strategy
  • JWT Token generation + validation
  • Route Guards + Custom Decorators

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🧩 09 - Database Relationships with TypeORM

• Expand Food Delivery App with Relationships
• Define OneToMany, ManyToOne, ManyToMany
• NestJS APIs to interact with related tables
• Combine with Auth, Middleware, Guards, Filters, and Interceptors

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🛠️ Requirements

• Node.js v18+
• Yarn or npm
• NestJS CLI
• Docker (for database sections)
• pgAdmin (optional)

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▶️ Running the App

# Install dependencies
yarn install

# Start the app
yarn start:dev

🧠 Learning Outcomes

• By the end of this course, you will:
• Understand NestJS core building blocks and architecture
• Be proficient in creating REST & GraphQL APIs
• Integrate multiple ORMs and databases
• Build real-world microservices with messaging and events
• Apply advanced patterns like Monorepo, Shared Modules, and Testing
• Secure APIs with authentication and authorization
• Handle middleware, guards, interceptors, filters professionally