Milestone 2: The Request Pipeline

🟦 Milestone 2: The Request Pipeline

Master the 5 layers that protect, transform, and monitor every request in a NestJS application.

🏗️ Core Modules

• Module 1: Validation Pipes: Transforming and validating data before it hits your controller.
• Module 2: Security Guards: Handling authentication and authorization logic.
• Module 3: Exception Filters: Standardizing error responses across the entire system.
• Module 4: Interceptors & Middleware: Logging, mapping, and transforming your response stream.

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Milestone Goal

By the end of this milestone, you will be able to implement a “Bulletproof” request flow that automatically handles validation, security, and global error handling with zero boilerplate in your controllers.

Tip

The “Rule of 5”: Every request in NestJS follows a specific order: Middleware -> Guards -> Interceptors -> Pipes -> Controller -> Interceptors -> Filters. Mastering this order is the key to debugging complex apps.