#​799 — May 7, 2026

Read on the Web
Together with  Testdouble

Ruby Weekly

Ruby Concurrency: What Actually Happens — A from-the-ground-up tour of processes, Ractors, threads, and fibers. Concurrency is a common source of confusion, but this guide helps clear up when to reach for which primitive, complete with benchmarks, sequence diagrams, and traces of what happens behind the scenes.

Carmine Paolino

AI Uncertainty and Pressure Causing Existential Dread? — It’s real, and you’re not alone. C-suites pushing AI mandates without strategy. Teams with varying levels of fluency. AI workflows aren’t productive. Test Double offers confidential pairing sessions with experienced humans. Safe space. No judgment.

Test Double sponsor

How Stripe Formatted a 25 Million Line Codebase Overnight — Stripe boasts ‘the world’s largest Ruby codebase’ (42 million lines in 2026), so how it reformatted all its code in a weekend using rubyfmt is quite the tale. This was before rubyfmt migrated to Prism, so it's even faster now.

Tales and Mason (Stripe)

⚡️ IN BRIEF:

An Overview of Spinel, Matz's AOT Ruby Compiler — Spinel intrigued me enough last week to dig deeper. Here’s a roundup of how it works, where it came from, what it can and can’t do, and where it could eventually fit into the broader ecosystem. Since last week it’s gained FFI support, and someone’s even written a CRuby extension with it!

Peter Cooper

Hanami and Friends Join Forces as Hanakai — The Hanami framework, Dry, and ROM have all come together under one group to form Hanakai, a single group that will grow that garden of aligned gems together.

Tim Riley

Surviving Black Friday: 329 Billion Requests with Falcon — A RubyKaigi slide deck from the creator of Falcon, a high-performance, multi-process, multi-fiber HTTP server built for Ruby apps. Shopify is now using it to scale its 15-year-old Rails codebase to incredible levels of traffic.

Samuel Williams

Onboarding Legacy Rails Apps Faster with AI — How SINAPTIA uses AI to understand legacy systems faster and start delivering value sooner. Let's talk.

SINAPTIA sponsor

📄 Asset Pipelines: Just Say No – “I will not be using any frontend bundling nor JS runtime at all. Here’s how you can do the same.” Julik Tarkhanov

📄 Avoid html_safe With Tag Helpers, safe_join, and sanitize Andy Croll

📄 Setting Up AppSignal Server Monitoring for a Rails App on Hatchbox Samuel Mullen (AppSignal)

🛠 Code & Tools

🤖 RubyLLM 1.15.0: Now with Image Editing and Cost Tracking — The popular ‘one stop shop’ API for working with AI models and APIs from Ruby makes it easier to edit existing images with paint, and there are now first-class ‘cost helpers’ to get running costs from response, chat, and agent objects.

Carmine Paolino

Plug Claude or Cursor into Your Rails App's Production Errors — AppSignal MCP feeds your AI the error, trace, and deploy. AI drafts the fix. You review and ship.

AppSignal sponsor

Kamal-Backup: Scheduled Rails Backups for Kamal Apps — A gem and a Docker image that provide scheduled database and Active Storage backups for Rails apps deployed with Kamal.

Carmine Paolino

Fuik: A Webhook Engine for Rails — A Rails engine that catches and stores webhooks from any provider, then gives you a clean way to process them.

Rails Designer

  • 🖼️ RMagick 7.0 – The long-standing Ruby interface to ImageMagick drops Ruby 3.1 (and older) as well as old ImageMagick versions.

  • SQLite3 v2.9.4 – Ruby bindings for SQLite 3.53.1 (notably you can now use ALTER TABLE to add/remove NOT NULL and CHECK constraints.)

  • SuperDiff v0.19.0 – Get a clear view of differences between complex data structures in RSpec.

  • minitest-hooks 1.5.4 – before_all/after_all/around_all hooks for Minitest.

  • factory_bot 6.6 – The library for setting up Ruby objects as test data.

  • rubyzip 3.3 – Read and write ZIP files from Ruby.

  • elasticsearch-ruby 9.4 – Numerous API updates.

📰 Classifieds

💫 Lessons-learned: Jon from Judoscale shares what they’ve learned from a decade (!) autoscaling thousands of apps.

🔬 "Absolutely essential for AI agent-written PRs." Undercover CI flags untested methods in every pull request. Free for open source.

💎 Elasticsearch-quality Full-Text Search for Postgres, now with native ActiveRecord support.