Tutorials
Writing custom RuboCop rules in 2026—Martian Chronicles, Evil Martians’ team blog
Write and ship modern custom RuboCop cops in 2026: learn the new plugin system, requires_gem API, InternalAffairs best practices, safe autocorrection nuances, and design trade-offs for building robust, future-proof lint rules.
A quick DEMO of Ruby-LibGD v0.2.4. – Linking Ruby knowledge from the most remote places in the world.
Not a tutorial, not a benchmark — just experimenting with 2D and 3D rendering in Ruby and confirming that the foundation is already mature and reliable. Links: # frozen_string_literal: true require….
The timezone bug that hid in plain sight for months | Arkency Blog
We recently fixed a bug in a financial platform’s data sync that had been silently causing inconsistencies for months. The bug was elegant in its simplicity: checking DST status for “now” when converting historical dates.
The broken code
I found ...
Use StringInquirer for Readable Predicate Methods - Andy Croll
You’ve probably seen Rails.env.production? in your codebase to ensure that certain code only runs in production. Instead of having to compare strings, Rails.env == "production", Rails wraps the string in an ActiveSupport::StringInquirer so you get...
How We Improved Rails Response Times by 87% — Fast Retro Blog
The whole observability setup lives on a single server, locked behind Tailscale so nothing is exposed to the public internet. I deploy it with Kamal 2 — the same tool I use for Fast Retro itself.
The stack has four pieces:
Prometheus — scrapes m...
Build a Resumable CSV Import with ActiveJob::Continuable | Code With Rails
Long-running background jobs have an uncomfortable relationship with deploys. You kick off a 100,000-row CSV import, deploy new code five minutes later, and the worker restarts. The job either starts over from the beginning or silently dies. Most ...
evilmartians.com/chronicles/tutorialkit-rb-the-ruby-wasm-journey-goes-onward
Ruby and WebAssembly are both powerful technologies, but together they unlock vast new possibilities. Evil Martians continue pursuing our goal of making ruby.wasm beneficial to the broader Ruby community (and beyond). To that end, we’d like to int...
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