--- title: "An early look at Ruby 4.0 and RubyGems 4.0" publication: "Ruby Weekly" issue: 776 published_at: "2025-11-20" canonical_url: "https://rubyweekly.com/issues/776" --- Plus you can nominate a Rails Luminary for 2025. | #​776 — November 20, 2025 [Read on the Web](https://rubyweekly.com/issues/776) Together with [![Makandra\](https://res.cloudinary.com/cpress/image/upload/c_fill,g_auto,e_trim,w_600,h_108/e_make_transparent/co_white,e_outline:12/hu5uh27ooxnubv3imdhe.png)](https://railslts.com/en/active-maintenance-763?utm_campaign=rails-maintenance&utm_source=rubyweekly&utm_medium=paid&utm_term=rails-lts) Ruby Weekly [![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60,q_auto/o0njhqokbgg1e4vdnjtu.jpg)](https://www.ruby-lang.org/en/news/2025/11/17/ruby-4-0-0-preview2-released/) [Ruby 4.0.0 Preview 2 Released](https://www.ruby-lang.org/en/news/2025/11/17/ruby-4-0-0-preview2-released/) — I never saw a preview _1_, but following Matz’s announcement of Ruby 4.0 two weeks ago at [RubyWorld](https://2025.rubyworld-conf.org/en/), we get an early release to play with – here’s [an initial set of release notes](https://docs.ruby-lang.org/en/master/NEWS_md.html) covering the changes introduced so far, which we'll focus on more in future issues. Yui Naruse 💎 [RubyGems 4.0.0 Beta 1](https://blog.rubygems.org/2025/11/20/4.0.0.beta1-released.html) has also been released. [![\](https://res.cloudinary.com/cpress/image/upload/c_limit,w_480,h_480,q_auto/copm/b7cf6685.png)](https://railslts.com/en/active-maintenance-763?utm_campaign=rails-maintenance&utm_source=rubyweekly&utm_medium=paid&utm_term=rails-lts) [Active Maintenance: We Take Care of Your Rails App](https://railslts.com/en/active-maintenance-763?utm_campaign=rails-maintenance&utm_source=rubyweekly&utm_medium=paid&utm_term=rails-lts) — With Rails LTS Active Maintenance we handle upgrades, tests, and performance so your team can focus on building. Reliable, secure, and always up to date – we keep your Rails app running smoothly. Rails LTS Active Maintenance by makandra sponsor [Compiling Ruby to Machine Language](https://patshaughnessy.net/2025/11/17/compiling-ruby-to-machine-language) — Another excerpt from the upcoming second edition of _Ruby Under a Microscope_ that discusses how YJIT optimizes “hot spots” in your code by compiling them to machine language. Pat Shaughnessy **⚡️ IN BRIEF:** - 🌍 [Ruby Around the World](https://rubyaroundtheworld.com/) is a new YouTube channel and newsletter dedicated to profiling Rubyists around the world. [▶️ The first episode](https://www.youtube.com/watch?v=TQBUNn-qJp8) features Okura Masafumi, the organizer of Kaigi on Rails, and touches on the Japanese side of the Ruby community. - 🏆 Two years ago, Rails [launched](https://rubyonrails.org/2023/8/8/introducing-rails-luminaries) the _Rails Luminary Awards_ to celebrate contributors to the ecosystem. Akira Matsuda and Matz himself [won last year](https://rubyonrails.org/2024/9/27/2024-rails-luminary-awards-matz-and-akira), but now you can [nominate someone for the 2025 Rails Luminary Awards.](https://rubyonrails.org/2025/11/14/2025-rails-luminary-nominations) Submissions close December 3. - 📕 David Bryant Copeland makes a point of noting that his book, _Sustainable Web Development with Ruby on Rails_, is [now out of print and will not be updated.](https://sustainable-rails.com/out-of-print.html) It's now a collector's piece! - 🇫🇮 If you're in Helsinki, head down to tomorrow's [tiny ruby conf](https://helsinkiruby.fi/tinyruby/) for some Ruby fun. - [Ruby Central shares its final weekly update](https://rubycentral.org/news/ruby-central-weekly-update-friday-november-14-2025/) before going back to a monthly cadence and answers a few more community questions. [![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60,q_auto/h3q1eq6x6xa6wtfwwgd0.jpg)](https://www.datadoghq.com/blog/ruby-performance-optimization/) [Performance Observations from Thousands of Real-World Ruby Apps](https://www.datadoghq.com/blog/ruby-performance-optimization/) — This is quite high level but has some interesting aggregated results from Datadog’s monitoring of a few thousand Ruby apps, including which libraries cause the highest share of CPU usage and median CPU usage by Ruby version. Anjo, Bauer, et al. (Datadog) [Context: The Missing API in Ruby Logger](https://honeyryderchuck.gitlab.io/2025/11/12/context-missing-api-in-logger.html) — Logging in Ruby and Rails is functional, but could be improved. After pointing out some deficiencies, Tiago proposes (complete with PR) a new logger API that allows the addition of context to each entry, bringing feature parity to other languages’ loggers. Tiago Cardoso [Tuple - The Fastest Way to Review AI Slop](https://tuple.app/l/pair-programming?utm_source=cooperpress&utm_medium=newsletter&utm_campaign=ruby_weekly_sponsored_20251120) — Wasting hours debugging AI code? Tuple brings your team together to figure it out, clean it up, and ship. Tuple sponsor 📄 [New in Rails 8.1: Bring Your Favorite Editor to Error Pages](https://glaucocustodio.github.io/2025/11/20/new-in-rails-8.1-bring-your-favorite-editor-to-error-pages/) – Set the `RAILS_EDITOR` env variable for your editor (from [these choices](https://github.com/rails/rails/pull/55295/commits/b22fd5a519f92e5c51c62e3b74b4407e492b89e2#diff-12428633edadb558b69eac4d099a36a54c632965bfd9af7ea1278818df42d1ebR56-R68)) and a link on the error page will open it to the relevant file. Glauco Custodio 📄 [Upgrading a 200 GB Postgres Database in 10 Minutes on Heroku](https://rosenfeld.page/articles/2025_11_16_upgrading_200_gb_postgres_within_10_minutes_in_heroku) Rodrigo Rosenfeld Rosas 📺 [Using `extend self` in Modules](https://gorails.com/episodes/module-extend-self) – Brief 5-minute tutorial. Colin Jilbert 🛠 Code & Tools [![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60,q_auto/l3z04mn72o49rf7uvb1y.jpg)](https://github.com/furunkel/zig.rb) [zig.rb: Write Type-Safe Native Extensions in Zig](https://github.com/furunkel/zig.rb) — Tired of writing native extensions in C? [Zig](https://ziglang.org/) makes for an interesting alternative, while still being familiar to C developers. furunkel [Grape 3.0: Opinionated Framework for Creating REST-Like APIs](https://github.com/ruby-grape/grape) — Grape can run on Rack or be easily pulled into existing apps using Rails or Sinatra, say, and provides a neat DSL to specifically build RESTful APIs. It’s also turned fifteen years old. [v3.0](https://github.com/ruby-grape/grape/blob/master/CHANGELOG.md#300-2025-11-15) includes a lot of tidying up, as well as Rack 3.2 support. Michael Bleigh [🧠 Smart Rails Applications Are Not the Future, They're the Present](https://sinaptia.dev/posts/building-intelligent-applications-with-rails?utm_source=cooperpress&utm_medium=newsletter&utm_campaign=rubyweekly-2025q4&utm_content=sponsored) — We identify problems worth solving with AI and [implement cost-effective solutions](https://sinaptia.dev/blog/tags/ai/?utm_source=cooperpress&utm_medium=newsletter&utm_campaign=rubyweekly-2025q4&utm_content=sponsored) that save significant organizational time. SINAPTIA sponsor - ⚠️ [Phusion Passenger gets a new signing key](https://blog.phusion.nl/important-new-signing-key-for-passenger/) – An important update for those installing Passenger via package systems. - 💬 [Slack Ruby Client 3.1](https://github.com/slack-ruby/slack-ruby-client) – Access Slack's Web, Real Time Messaging and Event APIs in Ruby or via a CLI. - [PublicSuffix for Ruby v7.0](https://github.com/weppos/publicsuffix-ruby) – Domain name parser for Ruby based on the Public Suffix List. - [Simple Scheduler 2.0](https://github.com/simplymadeapps/simple_scheduler) – Enhanced scheduling for Heroku Scheduler and Sidekiq. - [Bullet Train 1.37](https://github.com/bullet-train-co/bullet_train/releases/tag/v1.37.0) – Open source Rails SaaS-app template. ([Docs and demo.](https://bullettrain.co/)) - [PgParty 1.10](https://github.com/rkrage/pg_party) – Create and manage Postgres partitions from Active Record. - [Gon 6.6](https://github.com/gazay/gon) – Get your Rails variables into your JavaScript. - [Stripe Ruby 18.0](https://github.com/stripe/stripe-ruby) – Stripe's official Ruby library. 📰 Classifieds Can your architecture handle what's next? Everything feels urgent—so what's important? [Maybe it’s time to fix things so you can move faster](https://link.testdouble.com/4396d3). --- 🛣️ _[The Road to Next.js](https://www.road-to-next.com/?utm_source=ruby_weekly&utm_medium=newsletter&utm_campaign=next_course)_ is a course by Robin Wieruch for learning full-stack web development with Next.js 15 and React 19. 📢 Elsewhere in the ecosystem Some other interesting stories in the broader landscape: - [The latest version of Visual Code, v1.106, is out.](https://code.visualstudio.com/updates/v1_106) You can now select deleted code in diffs, 'snooze' inline suggestions directly from the gutter icon, the 'Go to Line' command gets some improvements if you want to go to a certain byte or column offset, and [Terminal IntelliSense](https://code.visualstudio.com/updates/v1_106#_terminal-intellisense) is now considered stable. - [Git 2.52 has been released](https://github.blog/open-source/git/highlights-from-git-2-52/) with a variety of minor features, including a new `git last-modified` command for determining which commit most recently modified each file in a given directory. - 🤖 Google introduced the hotly awaited preview of [Gemini Pro 3](https://blog.google/products/gemini/gemini-3-collection/) earlier this week. My experiments show it functions very well for coding purposes. [Here's a developer-oriented guide](https://ai.google.dev/gemini-api/docs/gemini-3?thinking=high) to what's new. GitHub Copilot has also [already added support.](https://github.blog/changelog/2025-11-18-gemini-3-pro-is-in-public-preview-for-github-copilot/) - 🤖 Meanwhile, Linus Torvalds says that [vibe coding is OK, just not for kernel development.](https://www.theregister.com/2025/11/18/linus_torvalds_vibe_coding/) - [A comparison of using Electron vs Tauri](https://www.dolthub.com/blog/2025-11-13-electron-vs-tauri/) for distributing a production desktop app. 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/).