What is middleware chaining in Express?

Short answer: Express allows multiple middleware functions to run sequentially for a request. Each calls next() to pass control to the next middleware. app.use((req, res, next) => { console.log('Middleware 1'); next(); }); app.use((req, res, next) => { console.log('Middleware 2'); res.send('Done'); });

Real-world example (ShopNest)

Express middleware authenticates JWT, then the /orders route handler creates the order.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.