--- title: "Say hello to ZJIT" publication: "Ruby Weekly" issue: 750 published_at: "2025-05-15" canonical_url: "https://rubyweekly.com/issues/750" --- Plus Ruby 3.4.4, Shopify's new AI framework, and computing astronomical data from Ruby. | #​750 — May 15, 2025 [Read on the Web](https://rubyweekly.com/issues/750) Together with [![Testdouble\](https://res.cloudinary.com/cpress/image/upload/c_fill,g_auto,w_1280,h_279/e_make_transparent/co_white,e_outline:32/fuxab1jg21v6anerbqwg.png)](https://link.testdouble.com/2656d6) Ruby Weekly [![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60,q_auto/rbti8pb74kbidx6mrbtv.jpg)](https://bugs.ruby-lang.org/issues/21311) [A Proposal for Defining Virtual Top Level Namespaces](https://bugs.ruby-lang.org/issues/21311) — The idea is that defined namespaces can load libraries and dependencies and keep them separate from other namespaces. Numerous benefits are promised like avoiding issues with globally shared objects, name conflicts, or version conflicts. There’s an interesting blend of support and criticism in the responses. Satoshi Tagomori et al. [![\](https://res.cloudinary.com/cpress/image/upload/c_limit,w_480,h_480,q_auto/copm/1ba710e4.png)](https://link.testdouble.com/2656d6) [Rails Upgrades: The Good Parts](https://link.testdouble.com/2656d6) — Trust the agency behind the Standard Ruby tools used by 20,000+ projects. Complex upgrades for GitHub, Gusto, and Zendesk. We set you up for independent, painless, and iterative future upgrades. Flexible contracts, no retainers, no subscriptions. Test Double sponsor [ZJIT Has Been Merged Into Ruby](https://railsatscale.com/2025-05-14-merge-zjit/) — ZJIT, a new JIT compiler from the YJIT team, has just been merged into Ruby after [Matz’s approval.](https://bugs.ruby-lang.org/issues/21221) ZJIT takes a different, more traditional approach to YJIT – all explained in the post – with the hope of being easier for developers to understand and contribute to. Both ZJIT and YJIT should be in Ruby 3.5, but this development lays the ground for the future. Max Bernstein [Ruby 3.4.4 Released](https://www.ruby-lang.org/en/news/2025/05/14/ruby-3-4-4-released/) — The latest minor release includes a fix for a YJIT bug as well as a build issue on Windows. Due to the importance of these fixes, it has been released ahead of schedule, meaning Ruby 3.4.5 is now expected in July. Takashi Kokubun **IN BRIEF:** - 🇳🇱 Last week we mentioned the schedule for [_Rails World_](https://rubyonrails.org/world/) tickets to be released, and we hope you got lucky as they all sold out in hours – again! - [The Rails project has adopted](https://rubyonrails.org/conduct) Ruby's community guidelines for conduct. 🤖 [Building a 'Coding Agent' in 94 Lines of Ruby](https://radanskoric.com/articles/coding-agent-in-ruby) — Inspired by a Go article that used 100 lines, Radan shows how Ruby can be used to build a (somewhat) functional coding agent in even _fewer_ lines of code. It leans a lot on [RubyLLM](https://github.com/crmne/ruby_llm), but this is still very cool. Radan Skorić [Serving Large Files in Rails with a Reverse Proxy Server](https://www.writesoftwarewell.com/serving-large-files-rails-nginx-thruster/) — Serving large files directly through an app is rarely the best or most efficient way to do it. Luckily, Akshay shows us a better way in quite some depth. Akshay Khot [All-in-one Ruby monitoring that helps you move fast and _fix_ things](https://www.honeybadger.io/?utm_source=rubyweekly&utm_medium=email&utm_campaign=2025-05-08-rubyweekly-link) — See why thousands of developers love Honeybadger. [Try our free developer plan →](https://www.honeybadger.io/plans/?utm_source=rubyweekly&utm_medium=email&utm_campaign=2025-05-08-rubyweekly-link) Honeybadger sponsor 📄 [Finding the Ideal Number of Threads Per Process using GVL Instrumentation](https://bigbinary.com/blog/tuning-puma-max-threads-configuration-with-gvl-instrumentation) Vishnu M (BigBinary) 📄 [An Introduction to Solid Queue for Rails](https://blog.appsignal.com/2025/05/07/an-introduction-to-solid-queue-for-ruby-on-rails.html) Hans-Jörg Schnedlitz (AppSignal) 📄 [Implementing a Mutex for Active Job](https://shivam.dev/blog/activejob-mutex) Shivam Mishra 📄 [My `puts` Debugging Workflow in Rails Apps](https://pawelurbanek.com/rails-puts-debug) Paweł Urbanek 📄 [Continuous Delivery for Gems](https://jcouball.substack.com/p/continuous-delivery-for-ruby-gems) James Couball 🛠 Code & Tools [![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60,q_auto/ufylfth4evd3nqsbtqda.jpg)](https://github.com/amazing-print/amazing_print) [Amazing Print 1.8: Pretty Print Your Ruby Objects with Style](https://github.com/amazing-print/amazing_print) — A fork of AwesomePrint that continues to get updates and an essential tool for ‘pretty printing’ Ruby objects. There’s nothing new but v1.8 formally adds Ruby 3.4 support. AmazingPrint 🔥 [Executing Structured AI Workflows with Shopify _Roast_](https://code.dblock.org/2025/05/10/executing-structured-ai-workflows-with-shopify-roast.html) — [Roast](https://github.com/Shopify/roast/) is a new framework for creating structured AI workflows which are defined in YAML files, for things like evaluating tests, static analysis, doc generation, and more. Daniel Doubrovkine [🤖 Make Your Next Heroku Upgrade Delightfully Boring with Bonsai](https://go.fastruby.io/zuc) — The humans behind [RailsBump.org](https://railsbump.org/)offer fixed-cost upgrade services. Let our AI-powered process get you there, faster. 🌳 Bonsai by FastRuby.io sponsor 🔭 [Astronoby 0.7: Compute Astronomical Data and Events](https://github.com/rhannequin/astronoby) — Load in ephemeris files that are used in astrometry to locate various space objects and calculate things like transit times, moon phases, and such things. The [project wiki](https://github.com/rhannequin/astronoby/wiki) provides some examples, as does [this blog series](https://dev.to/rhannequin/astronoby-v070-planets-and-ephemerides-85b) by Rémy. Rémy Hannequin [Semian: Added Resiliency When Calling External Services](https://github.com/Shopify/semian) — A library from Shopify we first linked exactly eight years ago! Semian intercepts resource access by several different libraries (e.g. mysal2, redis, Net::HTTP) and ‘fails fast’ when said external resources are slow or unresponsive. Shopify - 🤖 [Fast MCP 1.4](https://github.com/yjacquin/fast-mcp) – A Ruby implementation of the Model Context Protocol. - [rspec-openapi 0.19](https://github.com/exoego/rspec-openapi) – Make OpenAPI schemas from RSpec request specs. - [Delayed 1.0](https://github.com/Betterment/delayed) – A multi-threaded, SQL-driven Active Job backend. - [MemoWise 1.13](https://github.com/panorama-ed/memo_wise) – Performance optimized memoization library. - [Phlex 2.3](https://github.com/yippee-fun/phlex/releases/tag/2.3.0) – Object-oriented views in Ruby. ([Homepage.](https://www.phlex.fun/)) - [Gemirro 2.0](https://github.com/PierreRambaud/gemirro) – Create your own RubyGems mirror. - [parallel_tests 5.2](https://github.com/grosser/parallel_tests) – More cores == faster testing. - [Kamal 2.6](https://github.com/basecamp/kamal/releases/tag/v2.6.0) – The container-based app deployer. - [RubyGems 3.6.9](https://blog.rubygems.org/2025/05/13/3.6.9-released.html) 📰 Classifieds 🐌 [If your Rails team needs a little boost…](https://sinaptia.dev/services/staff-augmentation) We can augment your team with devs to help you keep up with your delivery schedule. [Test us!](https://sinaptia.dev/services/staff-augmentation) 📢 Elsewhere A quick roundup of some other interesting updates or useful resources in the broader developer landscape: - If you've got a color picker in your webapp, did you know it's possible to add [support for wide gamut P3 colors and alpha transparency?](https://www.webkit.org/blog/16900/p3-and-alpha-color-pickers/) - It's written in Go, but [fx](https://fx.wtf/) is a JSON viewing and processing tool I find very helpful and as of this week's [v36 release](https://github.com/antonmedv/fx/releases/tag/36.0.0) it now supports streaming JSON and tailing too. - [▶️ A quick, 4 minute demo](https://www.youtube.com/watch?v=uG5Vcjr5vxQ) of using GitHub Copilot's 'agent mode' in VS Code to build an app. - If you're tired of seeing React used everywhere, turn away.. but I found [tscircuit](https://tscircuit.com/) very interesting as it lets you lay out electronics circuit boards using JSX. - [Pinkerton](https://github.com/000pp/Pinkerton) is a Python-powered security auditing tool for looking through a site's JavaScript files for accidentally included secrets and tokens. P.S. If you happen to be at [Google I/O](https://io.google/2025/) next week, come and say hi if you see me about. I'm going to be there to see whatever Google has to announce! :-) Curated by [Peter Cooper](https://twitter.com/cooperx86) and [Glenn Goodrich](https://twitter.com/ruprict). Published by [Cooperpress](https://cooperpress.com/). [Change your email](https://rubyweekly.com/edit_subscription/*|UID|*) or [Stop getting this newsletter.](https://rubyweekly.com/leave/*|UID|*) © Cooper Press Ltd · Fairfield Enterprise Centre, Louth, LN11 0LS, United Kingdom Other weekly newsletters we publish include [Postgres Weekly](https://postgresweekly.com/), [React Status](https://react.statuscode.com/), [Frontend Focus](https://frontendfoc.us/), and [JavaScript Weekly](https://javascriptweekly.com/).