es-toolkit, From a Small In-House Library to a Globally Used Library

lodash, which is frequently used in frontend development, has the limitation of being inefficient, as it contains outdated code structures and unnecessary browser support logic that don't fit modern web environments.

The Toss team started the es-toolkit project to solve this problem. They aimed to support modern ECMAScript Modules and remove unnecessary logic to maximize performance and minimize bundle size.

Actual performance measurements showed that es-toolkit achieved the following remarkable results compared to lodash:

• Execution speed: improved by a minimum of 2x to over 10x, depending on the function
• Bundle size: reduced by more than 30x by removing unnecessary code

When the project was released based on these results, it received an explosive response from the overseas developer community as well, and it has now grown into an essential library recording over 20 million downloads per week, being used even in core libraries like Yarn and Recharts.