Questions
9 of 12
1How do you apply global middleware, pipes, guards, or interceptors in NestJS?
2What is the APP_GUARD / APP_PIPE token pattern in NestJS?
3What is the difference between app.use() and NestJS middleware?
4What is the difference between a service and a repository in NestJS?
5How does NestJS achieve platform agnosticism between Express and Fastify?
6How does the NestJS bootstrap sequence work?
7What is a barrel module in NestJS and when does it become an anti-pattern?
8How does NestJS resolve a provider when the same token is exported by two different imported modules?
9How do you implement a plugin system using dynamic modules in NestJS?
10How does NestJS handle module initialization order and can you control it?
11How do you unit-test a module that uses a dynamic module dependency in NestJS?
12What is the difference between a monorepo and a standard NestJS project structure?
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How do you implement a plugin system using dynamic modules in NestJS?

Define a plugin interface where each plugin returns a DynamicModule from a static register() method. A core module accepts an array of DynamicModule objects at import time, imports and re-exports all of them, allowing the application to be extended by assembling plugin modules in AppModule.

Plugin system using dynamic modules
Benefits of the dynamic plugin pattern:
  1. 1

    Open/closed principle — add plugins without modifying the core module.

  2. 2

    Each plugin is independently configurable via its register() options.

  3. 3

    Plugins are standard NestJS modules — they can declare controllers, guards, and interceptors.

  4. 4

    Plugin providers are available to the rest of the app through CoreModule re-exports.