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Since I wrote about async Ruby and patched Solid Queue to support fibers, people keep asking the same questions. What happens when a fiber blocks? Don’t you still need threads? What about database transactions? What about Ractors? This post answers all of it. From the ground up. The four primitives Ruby gives you four concurrency primitives: processes, threads, fibers, and Ractors. They nest. Ever

Four-time Formula 1 World Champion Max Verstappen heads to Japan’s legendary Fuji Speedway for a high-stakes challenge against a real Super GT pro. In brutal wet conditions, Max has one mission: beat the benchmark lap time set by a Japanese Super GT driver around one of the most iconic circuits in motorsport. But with standing water, zero grip, and visibility getting worse every lap, this turns i

☕ Welcome to The Coder Cafe! On April 3, 2026, Salvatore Dipietro, an engineer at AWS, posted a patch to the Linux kernel mailing list. The reason: on a 96-vCPU Graviton4 machine running Linux 7.0, PostgreSQL throughput had dropped to roughly half of what it produced on Linux 6.x. In this post, we will trace what changed in Linux 7.0, how PostgreSQL manages memory, and what role memory pages play

ShopifyはなぜFalcon移行に苦戦したのか？FiberとC拡張ブロッキング #rubykaigi2026 RubyKaigi 2026の「Surviving Black Friday: 329 billion requests with Falcon!」がFalcon gemの生みの親とそのチームが語るShopifyのunicornからFalconへの全面移行の戦いの記録で面白かったので深掘りしたい。本記事では、その発表で語られた事実を整理した上で、Falcon移行の本質である「Fiber Schedulerのフック対象外となるC拡張ブロッキング」を最小再現コードを交えて確認する。 ShopifyはFalcon（Webアプリケーションサーバのgem）を本番導入し、CPUコアあたりおよそ7%の効率改善を狙った。Shopifyのブラックフライデーは、ピーク時に毎秒142万リクエストに達

Async Rust is amazing, but far from flawless. In this blog, I'll walk you through the current struggles and possible solutions. So async Rust is amazing. It makes it possible to write code that can run concurrently with other code without having to manage dozens of manually written state machines. This is great for resource use. While waiting on data on a socket, the code won't spin or block a thr

How a $3.2M production disaster taught us that technical excellence doesn’t always align with business success — and why boring… How a $3.2M production disaster taught us that technical excellence doesn’t always align with business success — and why boring technologies often deliver better outcomes Senior engineers learn that the most technically impressive solution isn’t always the best business

はじめに ゲームサービス事業本部の三軒家です。 社内のとある Ruby on Rails プロダクトにて、ジョブキューシステムのバックエンドを Solid Queue に移行するプロジェクトを推進しています。 この記事では、Solid Queue への移行に際して実施した負荷試験の様子と、その結果として得られた Solid Queue のパフォーマンス特性に関する知見についてご紹介しようと思います。 TL; DR Solid Queue は、シングルスレッドな設定において、 1000 job/s 程度のスループットを安定して処理することができる 1000 job/s = 86400000 job/day なので、8000万 job/day ということになる 37signals1 の DHH氏は Tens of millions of daily HEY jobs now run off S