Callback hell is a situation in asynchronous programming where code becomes extremely difficult to read and maintain due to multiple layers of nested callbacks. This typically happens when you have several asynchronous operations that depend on each other, and each operation is placed inside the callback of the previous one. The result is code that forms a pyramid or "arrow" shape, making it hard to follow the logic, handle errors, or add new features. Here is how callback hell might look in practice:

To avoid callback hell in Node.js, you can follow several best practices:

• Use Promises to flatten nested callbacks and make asynchronous flows easier to reason about;
• Adopt async/await syntax for writing asynchronous code that looks and behaves more like synchronous code;
• Modularize your code by separating logic into smaller, reusable functions;
• Always handle errors properly at each step of your asynchronous operations;
• Prefer built-in Promise-based APIs or use utility libraries that promote clean asynchronous patterns. By applying these strategies, you can write Node.js code that is both maintainable and robust, even when dealing with complex asynchronous workflows.