Nodejs is one of the best runtime to make a powerful, fast and scalable applications. It is widely used in many fields and is powering a lots of application. It is very versatile and non opinionated so developers can use it as they like. But saying this the code or the architecture of the application can become very messy and hard to maintain and lots of performance issues could arise. So noting the issues on hand, I have addressed some topics which can help developers minimize messy code and performance issues and maximize the quality of the code. So lets dive in.

1. Use Asynchronous Code Wisely

Node.js is single-threaded and relies heavily on non-blocking I/O operations. Always prefer asynchronous methods over synchronous ones to avoid blocking the event loop. Synchronous code can block the event loop, causing delays in handling other requests. Asynchronous code ensures your app remains responsive.

If you don't like the callback system, you can always wrap the function in promise and then resolve it.

Example:

// Bad: Synchronous file read
const fs = require('fs');
const data = fs.readFileSync('file.txt'); // Blocks the event loop
console.log(data);

// Good: Asynchronous file read
fs.readFile('file.txt', (err, data) => {
  if (err) throw err;
  console.log(data);
});

---------------------------------------------------------------------------
// Read file with promise
const readFile=()=>{
  return new Promise((resolve,reject)=>{
    fs.readFile('file.txt',(err,data)=>{
      if(err) reject(err);
      resolve(data);
    })
  })
}

readFile().then((data)=>{
   console.log(data)
}).catch((err)=>{
   console.log(err)
})

2. Use Environment Variables for Configuration

Hardcoding configuration values (like API keys or database credentials) is a bad practice. Use environment variables to manage configurations securely. This keep sensitive information out of your codebase and make it easier to manage different configurations for development, testing, and production. Also use constants whenever possible to store repetitive information or variables such as PAGINATION_DEFAULT_LIMIT, PAGINATION_DEFAULT_SORTING etc.

Example:

// Install dotenv package: npm install dotenv
require('dotenv').config();

const dbPassword = process.env.DB_PASSWORD;
console.log(`Database password: ${dbPassword}`);

3. Handle Errors Gracefully

Unhandled errors can crash your Node.js application. Always use try-catch blocks or .catch() for promises to handle errors properly. Proper error handling ensures your app doesn't crash unexpectedly and provides meaningful feedback to users. Also alternatively you can wrap a custom middleware to catch errors also if you don't like writing try catch everywhere in the code.