Plus Tenderlove on Ractors and AI, React SSR in Rails without Node.js, and the Ruby Central dispute rumbles on.

#​812 — August 6, 2026

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Ruby Weekly

Shrinking Ruby HashesHash uses 2-4x the memory of a Struct holding the same data. Ruby committer Jean Boussier digs into why, looking at the layout changes from Ruby 2.3 to now, and shows off the patches that could shrink small hashes in Ruby 4.1.

Jean Boussier

Make Your Next Rails Crash Make Sense — Errors, N+1 queries, slow SQL, Sidekiq jobs, and host metrics in one Ruby gem. Every feature on every plan, predictable pricing, and real engineers on support. 30-day free trial, no credit card, two-minute install.

AppSignal sponsor

▶  Tenderlove on Ractors, JIT Compilers, and Installing Gems Faster — If you're an Aaron Patterson fan, there's much to enjoy in this 80-minute chat, covering his pre-Ruby background, Ractors, opinions on databases, making gems faster to install, and why he still can't trust AI code like a teammate's.

Robby Russell and Aaron Patterson

⚡️ IN BRIEF:

Making RubyGems Guides Friendly to Humans and AI — Append .md to any of the guides' URLs for raw Markdown, or point an agent at llms.txt for an index of them all. The guides have had a broader overhaul too, with a new Concepts section and Cmd+K search.

Hiroshi Shibata

Rails 7.2 Security Support Ends Aug 9. Need to Upgrade Fast? — “FastRuby.io successfully upgraded our application to Rails 8.1 and Ruby 3.4 on time and on budget.”

FastRuby.io® | Rails Upgrade Services sponsor

🤖 Tell the Agent to Write Its Scripts in Ruby – Scripts have always been a sweet spot for Ruby, so why not have your agents use it, too? Lucian Ghinda

📄 Running Code When the Rails Web Server Boots – That is, only under Puma, say, and not in rake tasks or the console. Ben Sheldon

📄 How to Install Any Ruby Version in Seconds Using rv Javier Cervantes

📄 Running a Ruby MCP Server in Production Amanda Bizzinotto

🛠 Code & Tools

Rubydex-Powered Project-Wide Analysis with RuboCop 1.89RuboCop has traditionally analyzed one file at a time, but its expanded, opt-in Rubydex support gives it a project-wide index, so cops can catch things like duplicate methods across files and typos in constant and method names.

Bozhidar Batsov

💡 Lovro Bikić also digs into how RuboCop 1.89.0 now loads cops lazily rather than requiring all 600+ at startup, for a 10-25% startup speedup.

redis-rb 6.0: The Official Ruby Client for Redis — Now speaks Redis' latest wire protocol RESP3 by default, adds first-class support for the Redis Query Engine and the JSON module, new Redis 6.2-8.10 commands, and more. Note that Ruby 3.2+ is now required.

Redis Ltd

🤖 Ask Your AI Editor What Broke — AppSignal's MCP server feeds live Rails errors, traces & metrics into Claude, Cursor & Copilot.

AppSignal sponsor

Humid 1.0: React Server-Side Rendering in Rails without Node.jsReact on Rails was too heavy, and a Node sidecar didn't appeal… so Johny built a solution using mini_racer's embedded V8 to render React with no Node process to manage at runtime.

Johny Ho (Thoughtbot)

📊 Flightdeck: A Featureful Dashboard for Solid Queue — A more visual, dashboard-like alternative to Mission Control, with throughput charts, failure grouping, bulk retry, and queue pause/resume. Drops in with no migrations or asset configuration.

Carl Mercier

📰 Classifieds

💎 Shipping Ruby code with AI agents? Undercover CI catches untested methods in your PRs before you merge. Coverage percentages won't.

📢  Elsewhere in the ecosystem