Question 1: Which Express configuration helps mitigate large payload attacks?
- res.set()
- body size limits
- app.param()
- router.use()
Explanation: Body size limits prevent payload abuse.
This advanced Express.js quiz is crafted for senior backend developers and engineers preparing for high-level interviews. It focuses on Express internals, middleware architecture, performance optimization, security, scalability, and real-world production scenarios.
Explanation: Body size limits prevent payload abuse.
Explanation: Synchronous logging blocks request handling.
Explanation: Async structured logging scales well.
Explanation: Idempotency avoids repeated side effects.
Explanation: PUT is idempotent by definition.
Explanation: Queues offload long-running tasks.
Explanation: Shared state causes race conditions.
Explanation: Fail-fast allows recovery via restarts.
Explanation: Uncaught exceptions can corrupt process state.
Explanation: Restart ensures a clean state.
Explanation: Environment configs prevent hardcoding secrets.
Explanation: Lazy loading defers heavy work.
Explanation: Failures may go unnoticed without monitoring.
Explanation: Latency and errors indicate API health.
Explanation: Compression consumes CPU resources.
Explanation: Production readiness requires monitoring and shutdown handling.
Explanation: Express provides a minimal and flexible backend framework.
Explanation: Synchronous logic blocks the event loop and delays other requests.
Explanation: Express provides a higher-level abstraction over Node’s HTTP module.
Explanation: Middleware execution depends on declaration order and route matching.
Explanation: Each middleware adds processing overhead to every request.
Explanation: Worker threads prevent CPU-heavy tasks from blocking the main thread.
Explanation: Centralized error handling ensures consistent responses and logging.
Explanation: Unhandled async errors can leave requests unresolved.
Explanation: Errors must be forwarded using next(err) or async wrappers.
Explanation: Unvalidated input can lead to injection vulnerabilities.
Explanation: Validation blocks invalid or malicious requests early.
Explanation: Improper header handling can enable request smuggling attacks.
Explanation: In-memory sessions do not scale across multiple instances.
Explanation: External stores like Redis support horizontal scaling.
Explanation: Reverse proxies offload networking concerns from Express.
Explanation: Rate limiting protects APIs from abuse and denial-of-service attacks.
Explanation: Authentication must run before protected routes.
Explanation: eval-like logic can allow execution of malicious code.
Explanation: URL-based versioning is explicit and easy to maintain.
Explanation: Stateless apps scale more easily across multiple instances.
Explanation: Structured logs and metrics improve monitoring and debugging.
Explanation: Graceful shutdown allows active requests to complete.
Explanation: SIGTERM allows cleanup before process termination.
Explanation: Incorrect trust proxy settings can allow IP spoofing.
Explanation: Global middleware runs for every request, even when not needed.
Explanation: Service layers improve maintainability and testability.
Explanation: Parsing large JSON bodies can block the event loop.
Explanation: Body size limits prevent payload abuse.
Explanation: Synchronous logging blocks request handling.
Explanation: Async structured logging scales efficiently.
Explanation: Idempotency avoids repeated side effects on retries.
Explanation: PUT is idempotent by HTTP specification.
Explanation: Queues offload long-running tasks from request handling.
Explanation: Shared state can cause race conditions under load.
Explanation: Fail-fast allows recovery via process restarts.
Explanation: Uncaught exceptions can corrupt application state.
Explanation: Restarting ensures a clean and stable state.
Explanation: Environment configs avoid hardcoding secrets.
Explanation: Lazy loading defers expensive operations.
Explanation: Failures may go unnoticed without monitoring.
Explanation: Latency and error rate indicate API health.
Explanation: Compression consumes CPU resources.
Explanation: Production readiness requires monitoring and graceful shutdown.
Explanation: Express aims to be a minimal and flexible HTTP framework.
This advanced Express.js quiz is crafted for senior backend developers and engineers preparing for high-level interviews. It focuses on Express internals, middleware architecture, performance optimization, security, scalability, and real-world production scenarios.