Express.js

Express routing, middleware, REST APIs, auth, validation, and backend API exercises.

Study order: Routes → Request input → Middleware → Controllers → REST → Validation → Auth → Errors → API exercises

• What is Express? — What Express adds on top of Node.js and why it exists.
• Routing — Map HTTP methods and URLs to handler functions.
• Params, Query and Body — Understand where request input comes from.
• Middleware — How Express runs request logic in a chain.
• Controllers and Services — Separate HTTP handling from business logic.
• REST API Design — Design resource-based APIs using HTTP methods and status codes.
• Request Validation — Validate input before it reaches business logic.
• Error Handling Middleware — Centralize errors and responses in Express.
• Authentication and JWT — Verify user identity with tokens.
• Authorization — Control what authenticated users are allowed to do.
• CORS in Express — Allow controlled browser access from other origins.
• Pagination, Filtering and Sorting — Return large datasets in a controlled API shape.
• Cookie Sessions — Store auth state with cookies and server/session strategy.
• File Uploads in Express — Accept files safely using middleware and storage rules.
• Rate Limiting in Express — Protect APIs from repeated abusive requests.
• Security Headers — Use headers to reduce common web risks.
• Testing Express APIs — Test routes, middleware, and error responses.
• CRUD API — Build create, read, update, and delete routes.
• JWT Auth API — Build login, register, and protected routes.
• Role-based Authorization API — Restrict routes by user role.
• Pagination and Search API — Add query-based list controls to an endpoint.
• URL Shortener API — Build a common backend machine-coding project.