Ruby Weekly Issue 785: January 29, 2026

#785 — January 29, 2026

Together with

The Ruby Runway: A RubyConf Pitch Competition — RubyConf has launched a competition for Ruby-powered startups to take the stage at RubyConf and compete for various cash prizes and awards. You need to represent a business using Ruby at its core, and not have raised more than $500k so far. The submission deadline is February 28 — and if you can't enter, RubyConf is looking for reviewers and judges for the entries.

Ruby Central

Anyone Can Code: Software Is Having Its Ratatouille Moment — AI tools aren't replacing developers—they're being used to reframe who gets to build. Dave Mosher on why hoarding technical ability is the wrong response, and what quality really means when anyone can cook.

Test Double sponsor

Optimistic UI in Rails with Optimism and Inertia — Your users ~~want~~ expect snappy UIs and implementing a so-called ‘optimistic’ UI can help provide that experience, even while things are still working in the background. This post shows off using Inertia to make implementing an optimistic UI in a Rails app trivial in a mock Kanban board app called Izzy (inspired by Fizzy, we suspect!)

Svyatoslav Kryukov (Evil Martians)

💡 We somehow missed that Fizzy, 37signals’ newest app that launched last month, is also, like Campfire, an open-source-ish project, with a Rails codebase that you can install yourself or read to see 37signals’ in-house Rails style.

⚡️ IN BRIEF:

🔧 Ruby 4.0 is now available in the Microsoft Store, thanks to the efforts of the RubyInstaller for Windows project.
Want to chat with other Rubyists old-school forum style? The Ruby Users Forum has just launched.
🤖 Did you know there's a Ruby AI podcast? It's not AI generated, but hosted by three Rubyists and usually featuring a guest, such as this recent episode with Evan Phoenix.
Charles Nutter has been adding the ability to use a WebAssembly build of Ruby's Prism parser to JRuby as a way to maintain Ruby language compatibility without a native library requirement.
🇹🇭 RubyConf Thailand 2026 takes place this weekend (January 31 – February 1) in Bangkok. A few tickets remain.
🇫🇮 tiny ruby conf is headed back to Helsinki this October 1.

Ruby::Box: Rethinking Code Reloading With Isolated Namespaces — A rethinking of hot reloading a Ruby app that doesn’t fight Ruby’s global object space (thanks to 4.0’s experimental Box feature). It only supports simple Rack apps right now, but the author has hopes it could evolve.

Josef Šimánek

What Finally Posting Rails UI to Hacker News Taught Me — Practical advice on what to think about when sharing a project (in this case, a new commercial suite of components and themes for Rails) in a popular space.

Andy Leverenz

Rails Upgrade Plans Backed by 60,000+ Dev/Hours, Not AI Hallucinations — Real humans, real experience. Give your CFO a budget they can trust. A thorough action plan delivered in 2-3 weeks.

The Rails Upgrade Roadmap sponsor

📄 What 'Shoulda Matchers' Is Actually Doing For You – What code like it { is_expected.to ... } is actually doing behind the scenes. Matheus Sales

📄 A Simple Tailwind CSS Setup for Jekyll – How to set up Tailwind with Jekyll using the jekyll-tailwind gem. Andy Croll

📄 Rendering Seismic Observation Data with Ruby Giménez Silva Germán Alberto

📄 How I Actually Use AI to Write Rails Code Mario Alberto Chávez

🛠 Code & Tools

bundler-audit: Vulnerability Detection for Dependencies — A tool that goes through your Gemfile.lock and looks for vulnerable gems (using the Ruby Advisory Database), insecure gem sources, and provides advisory information. It even works offline and can output JSON for CI integration.

RubySec

Ruby Classifier 2.2: Text Classification Made Simple — A very long-standing project gets a major update with new classification options, better performance, and some new guides to get you started with k-Nearest, TF-IDF, LSI, and Bayesian classification.

Lucas Carlson et al.

Rails Deployments That Scale — Cloud 66 for Rails — Used by today's best Rails companies, with asset pipeline, console access, ActionCable & zero-downtime.

Cloud 66 sponsor

Mudis: Fast, Thread-Safe, In-Memory, Sharded LRU Cache — A pure Ruby in-memory cache (with a snapshot-based ‘soft persistence’ option). Useful for apps where a full Redis install is overkill for doing a little caching. Can integrate with Rails and Hanami.

Kieran Borsden

🤖 ChaosToTheRescue: LLM-Powered Method Generation and Rails Error Rescue Suggestions — “This experiment explores how much uncertainty Ruby code can tolerate before it stops feeling deterministic.” Please don't put this into prod! 😅

Valentino Stoll

xsv 1.2: Fast, Lightweight XLSX (Excel) Parser Library — A spreadsheet parsing library that sticks to the basics: “It strives to be minimal in the sense that it provides nothing a CSV reader wouldn’t.”

Martijn Storck

Devise 5.0 – Flexible authentication for Rails. A breaking release due to removing deprecations, dropping support for old versions of Ruby and Rails, and introducing Rails 8 support.
ActiveType v2.8.0 – Rails presenter and form model library providing ActiveRecord-like features for non-database-backed or extended models.
RubyCritic 5.0 – Get quality reports for Ruby code through static analysis.
AcceptLanguage – Accept-Language HTTP header parsing library.
Grape 3.1 – Opinionated framework for building REST-like APIs.
Dalli 4.2 – High-performance memcached client.
Redlock 2.1 – Redis-based distributed locking.
⭐ RubyGems 4.0.5 and Bundler 4.0.5
⭐ Rails 8.1.2

📰 Classifieds

🐡 Bloated jobs killing your worker memory? The “dedicated worker” pattern might help. (It worked for Justin.)

🔬 Shipping AI code? Undercover catches untested methods in your PRs before you merge. Coverage percentages won't. Free for open source.

📢 Elsewhere in the ecosystem

Some other interesting stories in the broader landscape:

Over on X, DHH posted the rails stats output (see above) for 37signals' flagship Basecamp app, which is now entering development for Basecamp 5. He says: "So that's now a 12(!) year-old code base, and we're able to run the entire test suite in just 45 seconds on a local 16-core AMD Linux box."
Julia Evans (the original creator of rbspy) wrote up her notes on starting to use Django and has some reflections on how it compares to Rails. She found Django's explicitness easier to return to after months away, but really appreciates both the ORM and the auto-generated admin interface.
OpenAI shares the story of how it's scaled Postgres to serve 800+ million users. The interesting technical point is they're only using a single primary (coupled with many read replicas) to do so.
A well-known JavaScript developer explained how he ported 100k lines of TypeScript to Rust using Claude Code. The languages aren't important; it's really about the insights in nudging agentic tools to get through such tasks.
🕹️ The creator of Three.js (known as mrdoob) has created a Three.js-powered port of 1996's Quake – here's the source. You can learn more about this project in this X thread.