When it comes to Node.js, leveraging the right modules can greatly simplify your development process. Below are 10 essential Node.js modules you should consider integrating into your projects:

1. Express: A minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.
2. Mongoose: An elegant MongoDB object modeling tool that provides a straightforward schema-based solution to model your application data.
3. lodash: A modern utility library delivering modularity, performance, and extras to ease your JavaScript operations.
4. nodemon: A utility that will monitor for any changes in your source and automatically restart your server, improving your development workflow.
5. jsonwebtoken: A compact, URL-safe means of representing claims to be transferred between two parties. It’s great for user authentications.

Continuing with our list of essential Node.js modules, here are five more that can significantly enhance your workflow:

6. axios: A promise-based HTTP client for the browser and Node.js that allows you to make HTTP requests easily.
7. dotenv: A zero-dependency module that loads environment variables from a .env file into process.env.
8. cors: A package that enables Cross-Origin Resource Sharing, allowing your Node.js application to relax the security applied by default.
9. body-parser: Middleware for Node.js to parse incoming request bodies in a middleware before your handlers, available under the req.body property.
10. socket.io: Enables real-time, bidirectional and event-based communication between the browser and server.

Building a real-time chat application with Node.js is an exciting project that allows developers to enhance their skills in handling WebSockets and asynchronous programming. To get started, ensure you have Node.js and npm installed on your machine. You'll begin by setting up a new project directory:

1. Create a directory for your chat application.
2. Run npm init -y to create a package.json file.
3. Install the required modules, mainly express and socket.io, using npm install express socket.io.

Once you have your environment set up, you can create a simple chat server using Node.js. Start by requiring the necessary modules in your server.js file. Use express to set up the server and socket.io to enable real-time communication. Example code snippet:

const app = require('express')();
const server = require('http').createServer(app);
const io = require('socket.io')(server);
server.listen(3000, () => console.log('Server running on port 3000'));

From here, you can implement events to handle user messages, allowing for an interactive chat experience.

Node.js, while known for its high performance, can encounter several common performance issues that developers should be wary of. One significant issue is the blocking I/O operations. When a blocking operation occurs, it can stall the event loop, preventing the Node.js application from handling other requests. To avoid this, it's essential to utilize asynchronous methods and to use the callback or Promise patterns effectively. Additionally, developers should consider employing the worker threads module or tools like Node Cluster to manage heavy computations without blocking the main thread.

Another common performance issue arises from memory leaks, which can degrade the efficiency of a Node.js application over time. Memory leaks often occur due to improper management of resources such as event listeners, or retaining references to objects that are no longer needed. To combat this, developers should implement regular memory profiling using tools like Node.js built-in profiler or external libraries such as Clinic.js. By identifying and resolving memory leaks, you can significantly enhance the overall performance and stability of your Node.js applications.