Middleware functions are the backbone of Express applications, providing a way to process requests before they reach route handlers. With over 25 years of experience in backend development and as the creator of CoreUI, I’ve built countless APIs that rely on middleware for authentication, logging, and data processing. The most effective approach is using app.use() to register middleware functions that execute in order for each request. This pattern provides modularity, reusability, and clean separation of concerns in your Express application.

Logging variables is fundamental for debugging JavaScript applications and understanding program flow during development. As the creator of CoreUI with over 25 years of JavaScript development experience, I’ve used console logging extensively for debugging complex UI interactions and data flows. From my expertise, the most effective approach is using console.log() with descriptive labels and leveraging advanced console methods for complex data structures. This practice provides immediate visibility into variable values and program execution.