Express interview practice.
Rehearse with explained interview questions. Describe the mechanism, trace an example, and explain a trade-off before revealing the answer.
How to use this session
- Choose a level and session length. Try each prompt before opening the notes.
- Compare your explanation with the source answer and revisit any concept you missed.
- Mark the questions you reviewed. Sign in to save session history; your draft answers stay in this page.
Code is provided for reading and tracing. These sessions do not execute or automatically grade code.
Express practice
Think first. Reveal second.
Explain your reasoning before opening the notes. A focused session lets you choose your question count; mock rounds follow the original guide.
1 questions match your selection.
Preview the Express question pool
- What happens during an Express request?
Express handles requests through a sequence of registered middleware and route handlers. Middleware can inspect or change the request, stop it with a response, or pass it onward. The order of registration matters because later handlers see the result of earlier ones.
- How should Express handle errors?
Error handling turns application failures into predictable responses and useful internal logs. Express uses error middleware with four arguments to handle errors passed into its request pipeline. Synchronous throws are handled by Express, while promise forwarding differs between Express 4 and 5.