--- title: "Ruby 4.1's first preview is here" publication: "Ruby Weekly" issue: 821 published_at: "2026-10-15" canonical_url: "https://rubyweekly.com/issues/821" --- Plus RuboCop gets a Web playground, ZJIT catches up with YJIT, and 37signals sandboxes Active Storage. #​821 — October 15, 2026 [Read on the Web](https://rubyweekly.com/issues/821) Together with [![Tiger Data logo\](https://res.cloudinary.com/cpress/image/upload/c_fill,g_auto,w_1280,h_282/e_make_transparent/co_white,e_outline:30/px1u7kjyvz7xnbm6ytir.png)](https://www.tigerdata.com/go/trial?utm_source=content-syndication&utm_medium=referral&utm_campaign=ruby-weekly-newsletter) Ruby Weekly [![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60,q_auto/unzcwumd2uagwgbxonoo.jpg)](https://www.ruby-lang.org/en/news/2026/10/12/ruby-4-1-0-preview1-released/) [Ruby 4.1 Preview 1 Released](https://www.ruby-lang.org/en/news/2026/10/12/ruby-4-1-0-preview1-released/) — Two months out from its final release, we get a 4.1 preview to play with, complete with [`Module#descendants`](https://bugs.ruby-lang.org/issues/9779), Ractor-local GC, YJIT on Windows, and a raft of smaller changes. Worth testing to shake out the effects of things like `Symbol#to_s` returning frozen strings and all `Regexp` instances being frozen too. Yui Naruse [![\](https://res.cloudinary.com/cpress/image/upload/c_limit,w_480,h_480,q_auto/copm/8868a1ef.png)](https://www.tigerdata.com/go/trial?utm_source=content-syndication&utm_medium=referral&utm_campaign=ruby-weekly-newsletter) [Your Rails App Doesn’t Need a Data Warehouse](https://www.tigerdata.com/go/trial?utm_source=content-syndication&utm_medium=referral&utm_campaign=ruby-weekly-newsletter) — Slow Rails reports usually get a warehouse and an ETL job. Now numbers lag and you run two systems. TimescaleDB extends the Postgres your app already uses, so analytics run on live data with plain ActiveRecord. [Get $1000 credit to start](https://www.tigerdata.com/go/trial?utm_source=content-syndication&utm_medium=referral&utm_campaign=ruby-weekly-newsletter). Tiger Data (creators of TimescaleDB) sponsor 📊 [ZJIT is Now as Fast as YJIT](https://railsatscale.com/2026-10-09-zjit-is-now-as-fast-as-yjit/) — Shopify is now running the [ZJIT compiler](https://docs.ruby-lang.org/en/master/jit/zjit_md.html) in production, where it matches or edges out YJIT on response time while using about 20% less JIT memory. Early and directional only, but a neat milestone. Max Bernstein **⚡️ IN BRIEF:** - 🔒 [RubyGems.org now shows security warnings](https://blog.rubygems.org/2026/10/15/rubygems-org-now-shows-security-warnings-for-gems.html) on gem version pages, with known advisories from OSV and malware labels on malicious releases. - There's a [proposal to speed up `Struct` and `Data`](https://bugs.ruby-lang.org/issues/22437) to narrow the performance gap with equivalent hand-written classes. - [gem.coop's 2027 Gem Fellowship](https://gem.coop/updates/8/) aims to fund 15 Ruby open source projects. Applications open December 1. - 🇧🇷 [Tropical on Rails](https://www.tropicalonrails.com/en) has announced its 2027 dates: March 18-19 in São Paulo. [Living in a Booming Time for Ruby](https://blog.julik.nl/2026/10/the-weimar-of-ruby) — Responding to DHH's Rails World keynote, Julik argues that the Ruby world is in the midst of a creative boom where the community is using AI to fix things and plug gaps that have sat open for years. Julik Tarkhanov [🚨 Rails 8.0 Support Ends Nov 7. Upgrades on Autopilot With AI](https://go.fastruby.io/awg) — Our AI agent ships small upgrade PRs that pass your test suite; you stay in control. Starting at $497/mo. [Join the beta](https://go.fastruby.io/awg). FastRuby.io® | AI-native Upgrades on Autopilot sponsor 📄 [Adding Custom Thor Commands to Your Rails App](https://island94.org/2026/10/adding-custom-thor-commands-to-your-rails-app) – One line in `config/boot.rb` enables discovery of commands in`lib/commands`. Ben Sheldon 📄 [Escape LIKE Wildcards with `sanitize_sql_like`](https://andycroll.com/ruby/escape-like-wildcards-with-sanitize-sql-like/) – Otherwise a search for `%` can match all rows… Andy Croll 📄 [Deploying a Roundhouse App with Kamal](https://greg.molnar.io/blog/deploying-a-roundhouse-app-with-kamal/) – Shipping Campfire as a Spinel-compiled binary. Greg Molnar 🛠 Code & Tools [![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60,q_auto/daeyzw7xsifklukl26kq.jpg)](https://metaredux.com/posts/2026/10/10/rubocop-1-92.html) [RuboCop 1.92 Makes Agents More Welcome](https://metaredux.com/posts/2026/10/10/rubocop-1-92.html) — There's a strong focus on making RuboCop easier for coding agents to drive, with richer JSON output, offense caps, an `--explain` option and a better MCP server. There's a 'mountain' of autocorrection fixes to help humans too. Bozhidar Batsov 💡 [RuboCop's homepage](https://rubocop.org/) has also been rebuilt and now features [a new playground](https://rubocop.org/playground/) _(pictured above)_ that runs RuboCop in your browser (thanks to `ruby.wasm`). [The New Relic Alternative With One Price and Every Feature Included](https://www.appsignal.com/alternative/new-relic-alternative?utm_medium=paid&utm_campaign=rubyweekly&utm_source=rubyweekly&utm_content=sponsored&utm_term=1015) — Errors, N+1s, Sidekiq, logs and host metrics in one gem. Unlimited users, free dev-to-dev support, [30-day trial](https://www.appsignal.com/alternative/new-relic-alternative?utm_medium=paid&utm_campaign=rubyweekly&utm_source=rubyweekly&utm_content=sponsored&utm_term=1015). AppSignal sponsor [Hot Cell 1.0: Securing Active Storage in the Age of AI](https://dev.37signals.com/hot-cell-1-0/) — A way to run risky file processing operations in a container with no network and a read-only filesystem. Your app passes it open file handles over a Unix socket. The upcoming Rails 8.2's Active Storage can switch to using it with a config change. Mike Dalessio (37signals) [Iodine 0.8: A C-Powered Ruby Server Built for Long-Lived Connections](https://github.com/boazsegev/iodine) — A big rewrite, with network I/O handled by a C event loop outside the GVL. Supports Rack apps, plus the author's event-driven [NeoRack](https://github.com/boazsegev/neorack) API for streaming without tying up Ruby worker threads. Boaz Segev 💡 [Falcon](https://github.com/socketry/falcon) is another option for handling many concurrent connections that uses fibers and the `async` gem, and supports HTTP/2. [scrap4rb: Find the Messy Tests in a Ruby Project](https://roberthopman.com/scrap4rb-find-the-messy-tests/) — A small tool, based on Uncle Bob's [SCRAP](https://github.com/unclebob/scrap), that scores Minitest tests for smells like missing assertions, heavy mocking and hidden helper work, then gives one piece of advice per file. Robert Hopman - [RailsPreFlight 0.1](https://syedaslam.com/posts/a-preflight-you-can-run/) – Reads a Rails app and tells you what stands between it and the Rails version you want. - [sqlite3-ruby 2.10](https://github.com/sparklemotion/sqlite3-ruby/releases/tag/v2.10.0) – Ruby's SQLite bindings. Now bundles [SQLite 3.54.0](https://www.sqlite.org/releaselog/3_54_0.html) and adds `Database#serialize` and `#deserialize` to return or populate a database with a binary string. - [Bullet 8.3](https://github.com/flyerhzm/bullet) – Detects N+1 queries and unused eager loading. Now supports the upcoming Active Record 8.2. - [Solid Errors 0.8](https://github.com/fractaledmind/solid_errors) – Self-hosted, database-backed error tracker for Rails. - [Cucumber 12.0](https://github.com/cucumber/cucumber-ruby/releases/tag/v12.0.0) – The plain-language BDD test tool. 📰 Classifieds Cut your Ruby CI times in half. [WarpBuild](https://www.warpbuild.com/start?utm_source=cooperpress&utm_medium=newsletter&utm_campaign=h2-2026&utm_content=rubyweekly-2026-10-15) runs GitHub Actions twice as fast at half the cost. [Get $50 in free credits](https://www.warpbuild.com/start?utm_source=cooperpress&utm_medium=newsletter&utm_campaign=h2-2026&utm_content=rubyweekly-2026-10-15) with code`START50`. --- Keep up to date with key releases in numerous tagged programming language ecosystems with the [GitHub Release Tracker](https://releasemonitor.org/). 📢 Elsewhere in the ecosystem [![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60,q_auto/uvwyrqs3eqxpieis3nz1.jpg)](https://carlosdanielpohlod.github.io/redgem-site/) - 🎮 [RedGem](https://carlosdanielpohlod.github.io/redgem-site/) is an experimental 3D game engine, with its own editor, where you write the gameplay in Ruby (via mruby). Exports games for Linux, Windows and Android. ([GitHub repo](https://github.com/carlosdanielpohlod/redgem)) - 🔒 Trail of Bits [tested whether 25 package managers notice a malicious repository tampering with packages](https://blog.trailofbits.com/2026/10/14/package-managers-have-an-integrity-problem/). Bundler passes if your `Gemfile.lock` has a `CHECKSUMS` section (the default for new lockfiles since Bundler 4), but plain `gem install` has nothing to check against. - 🤖 If you want something like Claude Code/Codex but independent, open and supporting a wider range of models, [OpenCode 2.0](https://anoma.ly/notes/opencode-2-0/) is a great option – you can [get started here](https://opencode.ai/). [Pi](https://pi.dev/) is also good if you want something minimal. - Lea Verou shows off [a neat way to use icons in web UIs](https://lea.verou.me/blog/2026/icons/) and do _all_ the inserting and tweaking with CSS with no HTML involved. - Ryan Bigg, author of [several Rails books](https://ryanbigg.com/books) and [Rails contributor](https://contributors.rubyonrails.org/contributors/ryan-bigg/commits), is [stepping away from tech](https://ryanbigg.com/2026/10/leaving-tech) after a wave of job rejections. 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/).