When building robust applications with Node.js, choosing the right packages is crucial to enhance functionality and streamline development. Here are 10 essential Node.js packages that can significantly improve your application's performance and development process:

1. Express: A fast, unopinionated, minimalist web framework for Node.js, making routing and middleware integration seamless.
2. Mongoose: This package provides a straightforward schema-based solution to model your application data and interact with MongoDB.
3. Socket.io: For real-time, bidirectional event-based communication, this library is perfect for applications needing instant updates like chat applications.
4. Passport: An authentication middleware for Node.js that simplifies authentication strategies.
5. Jest: A delightful JavaScript testing framework with a focus on simplicity that ensures your application code is reliable.

Continuing with our list of essential Node.js packages, we have:

6. Axios: A promise-based HTTP client for the browser and Node.js, perfect for making asynchronous requests.
7. Dotenv: A module that loads environment variables from a .env file into process.env, promoting better security practices.
8. Winston: A versatile logging library for Node.js that allows for multiple transports and levels, making debugging easier.
9. Cors: This package provides a middleware function to enable CORS (Cross-Origin Resource Sharing), which is essential for API development.
10. Next.js: A powerful framework for server-rendered or statically-exported React applications, enhancing the user experience.

Creating a RESTful API with Node.js is a powerful way to build web services that can communicate with various clients. To start, you need to install Node.js on your machine and set up a new project using npm (Node Package Manager). Once your project is ready, you can install the Express.js framework, which simplifies the creation of server-side applications and easily handles different HTTP requests. To establish your API routes, utilize the Express app.get(), app.post(), app.put(), and app.delete() methods to define the behavior of your API endpoints.

After setting up the basic structure, it's crucial to implement middleware for parsing incoming requests and handling errors. Additionally, consider using a database like MongoDB for storing your data, which can be easily integrated with Node.js through libraries like Mongoose. To ensure your API is performant and secure, don't forget to add authentication and validation layers. Finally, always test your API endpoints using tools like Postman or Insomnia to ensure they function as expected before deploying.

Troubleshooting common Node.js issues can sometimes feel daunting, especially for new developers. However, understanding some of the prevalent problems and their solutions can significantly enhance your development experience. Memory leaks are one such issue that can lead to performance degradation. To identify memory leaks, you can utilize Node.js built-in tools like the Node.js Inspector or third-party services such as Heapdump. Additionally, checking your code for callbacks or event listeners that are not properly removed can prevent memory-related issues.

Another common challenge in Node.js is callback hell, which can make your code difficult to read and maintain. This is often due to deeply nested callbacks in asynchronous code. To resolve this, developers can employ Promises or async/await syntax, which can help flatten the structure and improve readability. Additionally, using error handling mechanisms such as try/catch blocks can help in gracefully managing the errors that arise during asynchronous operations. Always remember, the key to troubleshooting is to stay methodical and utilize console logs for debugging.