Dev

pgvector and RAG, Explained Through a Real Knowledge Workflow

• Jiyu Yan
• Engineering
• 17 Jun, 2026

RAG sounds more mysterious than it is. The name means Retrieval-Augmented Generation. That is a long way to say: before asking an AI model to answer, first retrieve the most relevant source material,

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Ralph Loop as a Plan Queue

• Jiyu Yan
• Tools
• 24 May, 2026

Ralph Loop is the simple idea of putting an AI coding agent in a loop and giving it enough structure to keep making progress. My version is deliberately smaller than the

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Vertical Slice Architecture with Dependency-Cruiser

• Jiyu Yan
• Engineering
• 23 May, 2026

I like vertical slices because they make a feature easier to delete, move, or review. The folder structure is not the main value. The value is that the code for one workflow is not spread across ten u

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Codex anywhere with tmux, Termius, and Tailscale

• Jiyu Yan
• Tools
• 18 May, 2026

My current mobile Codex setup is deliberately simple: I use Termius on my phone to SSH into my own laptop, then run Codex inside a [tmux](https://gi

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Zod Beyond Validation

• Jiyu Yan
• Engineering
• 17 Apr, 2026

Zod is usually introduced as a validation library. That is true, but the more useful idea is boundary definition. A TypeScript type only helps after data is already inside the pro

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Localization in Product Apps

• Jiyu Yan
• Engineering
• 20 Mar, 2026

Localization is not only replacing English strings with another language. In a product app, language touches workflow. It changes labels, validation messages, dates, empty states, permissions copy, d

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