Latest posts
Recent writing, in chronological order
ponytail — Reading the Design of a Ruleset That Teaches Agents Not to Write
September 9, 2026
Reading ponytail, a ruleset that curbs over-implementation by AI agents, from its implementation rather than its README. The seven-rung decision ladder, the injection machinery that ships a single SKILL.md through three hooks, the path that carries the rules to subagents, and how the author rebuilt the benchmark under outside criticism and retracted the old '80-94% reduction' claim.
Japanese Web Fonts and Core Web Vitals — Fixing LCP and CLS by Measurement
June 14, 2026
Technical SEO is a perfect score, yet only Lighthouse Performance won't budge. Tracing the cause with chrome-devtools measurements, the LCP cause was the render-blocking of a Japanese Web font, and the CLS cause was a navbar logo with no dimensions. A record of rejecting the font-swap-as-cause theory by measurement and driving CLS to 0 without adding size-adjust.
I built a running-car animation in the hero
June 2, 2026
A record of building a running-car animation from scratch for the Docusaurus top hero. I componentize the SVG line art with svgr and drive the tire rotation and background parallax with pure CSS. From drawing backgrounds with CSS mask, a seamless infinite loop, theme-color following, all the way to prefers-reduced-motion support, explained for beginners.
A Claude Code Best-Practice Collection: How to Navigate shanraisshan/claude-code-best-practice
May 25, 2026
A map for reading shanraisshan/claude-code-best-practice (445 files), the GitHub Trending #1 curation collection, along five axes: directory structure, concepts, workflows, tips, and reports. Organized so you can pick the elements that match your level.
I changed the blog domain to notes.rewheel.dev
May 18, 2026
I changed my personal tech blog's domain from notes.rasshii.dev to notes.rewheel.dev. I share the naming, which matches the concept of "learning by reinventing the wheel," along with my decision process.
Series & Features
Key content organized systematically
Clean Code Guide (TypeScript Edition)
A complete guide to writing maintainable, readable TypeScript. Covers naming, function design, and the SOLID principles across 11 chapters.
Markdown Syntax Reference
A cheat sheet for the Markdown / Docusaurus extended syntax used on this site. Covers Mermaid, KaTeX, admonitions, and GitHub Alerts.
About
Yuki Igarashi (yuki / sanfu). Marketing engineer at Codmon Inc. Learning across the frontend, backend, infrastructure, and AI while improving the developer experience with an SRE mindset.