#​782 — January 8, 2026

Read on the Web

Together with  FastRuby.io

Ruby Weekly

Zverok's Guide to Language Changes in Ruby 4.0 — Each year, Victor produces a mammoth roundup of changes introduced in the latest Ruby release (Ruby 4.0, in this case). For a release that doesn’t have a huge amount of changes at the language level, he’s come up with some fantastic examples and this is a must-read, as always.

Victor Shepelev

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FastRuby.io | Upgrade Experts sponsor

ZJIT is Now Available in Ruby 4.0 — ZJIT is a new just-in-time (JIT) compiler built into the reference Ruby implementation and included as an optional feature in 4.0. It’s not faster than YJIT yet, but its architecture gives it a higher potential performance ceiling and enables more developers to be able to work on it.

Max Bernstein

⚡️ IN BRIEF:

A Ruby Regular Expression Engine — Kevin has been working on exreg, a pure Ruby regular expression engine that implements most of Onigmo’s features.

Kevin Newton

A Ruby YAML Parser — Not happy merely building a regular expression engine in pure Ruby (above), Kevin also turned his hand to creating a pure-Ruby implementation of a YAML 1.2 parser and emitter called Psych::Pure.

Kevin Newton

An Introduction to Ruby Parsing with Prism — Since Ruby 3.4, Prism is Ruby’s default parser, and here Matheus explains its advantages before showing us how to use it to lex and parse code ourselves to surprisingly fun ends (including implementing a simple emoji-based representation of Ruby!)

Matheus Richard

Ruby Errors? Fix ‘Em Fast for FREE with Honeybadger — Do you support web apps in production? We contextualize Ruby logs so you can fix errors fast. Get your FREE account →

Honeybadger sponsor

📄 Building an AI Agent Inside a 7-Year Old Rails App Catalin Ionescu

📄 Rails 7.2 Connection Pool Changes May Slow Down Your App geetfun

📄 How to Create a Markdown Editor in a Rails App Hans-Jörg Schnedlitz

🛠 Code & Tools

Charm Ruby: Glamorous Terminal Libraries for Ruby — If you’ve ever worked with Go, you’ll have encountered Charm’s fantastic libraries, including their Bubble Tea TUI framework. This is an attempt to bring a little of that Go charm to Ruby too. Note: This is not from Charm themselves; it’s from Marco Roth, well known for his work on Herb.

Marco Roth

Stepped: Rails Engine for Orchestrating Complex Workflows — A Rails engine, extracted from a production app, that orchestrates complex workflows as a tree of actions through Active Job.

Robert Starsi

🧠 Smart Rails Applications Are Not the Future, They're the Present — We identify problems worth solving with AI and implement cost-effective solutions that save significant organizational time.

SINAPTIA sponsor

Boxwerk: Experimental Box-Powered Ruby Package System — Ruby 4.0 introduced an experimental ‘box’ feature providing in-process separation of classes and modules. Boxwerk is the first attempt I’ve seen to put it to practical use.

David Cristofaro

executorch-ruby: Run PyTorch Models in Ruby — Provides bindings to ExecuTorch enabling you to run exported PyTorch models (.pte files) directly from Ruby apps.

Ben Garcia

  • RBS 3.10 – Ruby's type signature language. v3.10 ships with a pure C parser implementation and signature updates for Ruby 4.0.

  • Pry 0.16 – The popular runtime developer console and IRB alternative now supports Ruby 4.0.

  • sqlite3-ruby 2.9 – Ruby bindings for SQLite 3. v2.9 introduces native gem packages for Ruby 4.0.

  • ruby.wasm 2.8 – WebAssembly ports of CRuby for edge/browser use cases. Now with Ruby 4.0 too.

  • ruby-pg 1.6.3 – The Postgres client library now has binary gems for Ruby 4.0, and more.

  • Bullet Train 1.38 – Open source Rails SaaS-app template. (Docs and demo.)

  • Maxitest 6.2 & 7.1 – Minitest, but with lots of added features. Changelog.

  • Bridgetown 2.1 – The modern site generation framework.

  • Delayed 2.0 – Multi-threaded, SQL-driven Active Job backend.

  • Single Cov 2.0 – Check your code coverage on every test run.

  • httparty 0.24 – The long-standing HTTP API client library.

  • Rouge 4.7 – Pure Ruby code highlighting library.

📰 Classifieds

😴 Workers running 24/7? Put them to sleep and REDUCE YOUR COMPUTE by 35% or more! Judoscale autoscales Sidekiq, Solid Queue, etc.

📢  Elsewhere in the ecosystem

Some other interesting stories in the broader landscape: