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Interviews / Backend Engineering / What is the difference between `npm` and `yarn`?

Questions

Your Node.js service is unresponsive. How do you debug a blocked event loop?
Q C
What are streams and why are they useful in Node.js?
Q C
What is the difference between `require` and `import` in Node.js?
Q C
How does Node.js handle I/O operations?
Q C
What is the `Buffer` class and what is it used for in Node.js?
Q C
What is the difference between callbacks, promises, and async/await?
Q C
How do you handle errors in asynchronous Node.js code?
Q C
How do you scale a Node.js application?
Q C
Your Node.js service has a memory leak. How do you debug it?
Q C
What is the difference between `child_process` and `worker_threads`?
Q C
What is the difference between `npm` and `yarn`?
Q C
How do you secure a Node.js application?
Q C

What is the difference between `npm` and `yarn`?

conceptual Ecosystem Interactive Quiz Code Examples

The Scenario

You are starting a new Node.js project and need to decide whether to use npm or yarn as your package manager.

The Challenge

Explain the difference between npm and yarn. What are the pros and cons of each approach, and which one would you choose for a new project?

Wrong Approach

A junior engineer might think that they are interchangeable. They might not be aware of the historical context of why `yarn` was created, or the differences in performance and features between the two.

Right Approach

A senior engineer would be able to provide a detailed explanation of the differences between `npm` and `yarn`. They would also be able to explain the benefits of using `yarn` and would have a clear recommendation for which one to use in a new project.

Step 1: Understand the History

npm is the default package manager for Node.js. It was created in 2010 and has been the standard for many years.

yarn was created by Facebook in 2016 to address some of the shortcomings of npm at the time, such as performance and security.

Step 2: npm vs. yarn

Featurenpmyarn
PerformanceSlower than yarn in older versions, but has improved significantly in recent versions.Faster than npm in older versions, due to parallel package installation and caching.
Lock filepackage-lock.jsonyarn.lock
WorkspacesSupported in npm 7 and later.Supported in yarn since version 1.
Plug’n’Play (PnP)Not supported.A feature that allows you to run your project without a node_modules folder.

Step 3: Choose the Right Tool for the Job

For a new project, yarn is generally the better choice. It is faster, more secure, and has more features than npm.

However, npm has improved significantly in recent years, and the performance difference between the two is not as great as it used to be. If you are working on a project that already uses npm, there is no need to switch to yarn.

Practice Question

You are working on a large monorepo with many packages. Which feature of `yarn` would be the most helpful?