# YJIT: Building a New JIT Compiler for CRuby

DevFeed: [YJIT: Building a New JIT Compiler for CRuby](<https://devfeed.tech/articles/yjit-building-a-new-jit-compiler-for-cruby-1684.md>)

Original publisher: [Read original article](<https://shopify.engineering/yjit-just-in-time-compiler-cruby>)

Author: Maxime Chevalier-Boisvert

Published: 2021-10-14T18:30:00Z

Content type: article

Language: en

Sources: [Shopify Engineering](<https://devfeed.tech/sources/shopify-engineering.md>), [Shopify Engineering - Shopify Engineering](<https://devfeed.tech/sources/shopify-engineering-shopify-engineering.md>)

Topics: [Ruby](<https://devfeed.tech/topics/ruby.md>), [JIT](<https://devfeed.tech/topics/jit.md>), [Compiler](<https://devfeed.tech/topics/compiler.md>), [Shopify](<https://devfeed.tech/topics/shopify.md>), [GitHub](<https://devfeed.tech/topics/github.md>)

Tags: [compiler](<https://devfeed.tech/tags/compiler.md>), [efficiency](<https://devfeed.tech/tags/efficiency.md>), [github](<https://devfeed.tech/tags/github.md>), [jit](<https://devfeed.tech/tags/jit.md>), [performance](<https://devfeed.tech/tags/performance.md>), [ruby](<https://devfeed.tech/tags/ruby.md>), [shopify](<https://devfeed.tech/tags/shopify.md>)

## AI overview

The article introduces YJIT, a new just-in-time compiler being developed inside CRuby by engineers from Shopify and GitHub. It explains the motivation for improving Ruby performance and energy efficiency, contrasts YJIT with CRuby's existing MJIT, and describes YJIT's data-driven focus on performance hotspots in large Ruby on Rails applications.

## Source excerpt

A team of skilled engineers from Shopify and GitHub on YJIT, a new Just-in-time (JIT) compiler built inside CRuby.