Use the built-in debugger
Node.js comes with a built-in debugger that can be used from the command line.

Use a Node.js debugger tool
There are several third-party debugger tools, such as node-inspector and Visual Studio Code, that can be used to debug Node.js applications.

Console logging
The console.log() method is a simple and effective way to debug Node.js applications by logging values of variables and expressions.

Using breakpoints
Breakpoints can be set in the code to pause the execution and inspect the state of the application at that point.

Heap snapshots
Heap snapshots are a great way to understand the memory usage of your application and identify potential memory leaks.

Error handling
Make sure to add proper error handling in the code to catch and log any errors that might occur during runtime.

Profiling
Node.js has built-in tools, such as the profiler, to help identify performance bottlenecks and optimize the application's performance.

Use a logging library
A logging library, such as Winston or Bunyan, can be used to log messages from the application and make it easier to debug.

Debugging in production
Debugging in a production environment can be challenging, but it can be done using techniques like remote debugging or using logs to recreate the issue.

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