What’s Slowing Down Your Node.js App? Here’s How to Fix It

Node.js is known for its speed and efficiency, making it a popular choice for building fast, scalable applications. However, even the best-performing Node.js apps can hit performance snags, impacting user experience and system efficiency. This guide covers common reasons for Node.js slowdowns and practical solutions to get your app back up to speed.

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1. Blocking the Event Loop

Node.js is single-threaded, which means that blocking the event loop with long-running or resource-heavy code can severely impact app performance.

Symptoms:

• Delayed response times
• Hanging or lagging in requests
• High CPU usage for simple operations

Solution:

Use asynchronous code where possible, and consider offloading CPU-intensive tasks to separate processes or worker threads.

// Instead of a blocking loop
function calculate() {
  for (let i = 0; i < 1e9; i++) {}
}

// Use asynchronous processing
function asyncCalculate() {
  setImmediate(() => calculate());
}

2. Inefficient Database Queries