Backend · FOCUSED GUIDE
Learn Express.
Trace middleware and handle failures across the request lifecycle.
YOUR LEARNING PATH
Express essentials
Start with the essentials or pick the concept you need.
RECOMMENDED NEXTThe Express request lifecycle
Start learning01Express lifecycleExplore concepts
What you will study in Express
Focused lessons organized by concept. Start with the explanation, trace the examples, and check your recall before moving on.
Express lifecycle
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.