ExecutionContext

• Represents the current request lifecycle context.
• Can access:
  • request
  • response
  • handler
  • controller

const request = context.switchToHttp().getRequest();

Lifecycle

• Event loop
• Non-blocking I/O
• Scales well for I/O heavy workloads

Incoming Request
    ↓
Middleware
    ↓
Guards
    ↓
Interceptors (before)
    ↓
Pipes
    ↓
Controller
    ↓
Service
    ↓
Interceptors (after)
    ↓
Exception Filters
    ↓
Response

Middleware

Like Express middleware.

• Logging
• Raw request manipulation
• Adding headers

// equivalent in Spring: OncePerRequestFilter