Technical Writings

Technical notes, engineering case studies, and practical reflections arising from work with software, Linux servers, WordPress, web infrastructure, automation, artificial intelligence, and human–AI development workflows. These writings document not only finished solutions but also failures, debugging processes, design decisions, rejected alternatives, validation methods, and lessons learned from real systems. Alongside implementation details, they examine the broader principles behind reliable technical work: observability, recoverability, security, resource constraints, careful experimentation, and the relationship between human judgment and increasingly autonomous tools.

Deploying a Modular Generative Geometry Generator (Browser-Based)

~ YIN Renlong

After completing the mosaic and scattered-collage stages of my WordPress Background Studio, I began asking a different question: could the system choose a mathematical composition method as well as choosing media? That question changed the project’s category. What began as background randomization became a modular browser-based generative-art engine with twelve algorithms, deterministic seeds, record-aware identity and a deployment process designed for a live, resource-constrained server.

I described the earlier evolution from a repeating background to mosaics and random collage in…
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Rethinking Yin’s Background Studio with Agentic AI (When the Harness Joins the Project)

~ YIN Renlong

I built Yin’s Background Studio through a semi-automated conversation: AI proposed bounded changes, I ran them on a live WordPress server, and the resulting logs and screenshots determined the next move. The system eventually grew from one repeating background into classic mosaics, scattered collage, persistence, density and colour controls. Now I want to try the next workflow seriously: let an agent inspect, edit, run, see and verify the project itself.

The existing method is my evidence base, not the method…
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From Patch-and-Verify to Managed Agents, and What I Would Automate Now

~ YIN Renlong

After building a multi-site WordPress backup system through a long patch-and-verify conversation, I wanted to revisit the entire process without assuming that its present form deserved to survive. Managed agents can now maintain state, operate tools inside sandboxes, enforce hooks, delegate evaluation and continue for hours. What would happen if that infrastructure were applied to the same project? Which manual loops would disappear, which controls would move into code, and where would human judgment change?

This is a comparison, not…
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An Inspectable Human–AI Workflow: Agency, Evidence, and Judgment in an AI-Assisted Project

~ YIN Renlong

Over several days, I built a centralized WordPress backup system by working with AI one verified change at a time. The AI wrote a great deal of Bash, Python, PHP and JavaScript, but it never independently controlled the production server. I inspected the evidence, ran each bounded operation, questioned incorrect diagnoses and decided when a procedure was finally reliable enough to automate.

This was neither ordinary manual coding nor fully agentic development

When people discuss AI-assisted programming, they often imagine…
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Designing a Central WordPress-to-GitHub Backup Plugin

~ YIN Renlong

New function updated: the centralized backup dashboard can now schedule all four WordPress backups automatically. The system runs them sequentially during an off-peak UTC window, while the existing global lock remains the final authority. In other words, four websites may queue politely, but they are not allowed to charge through the VPS door together.

Automatic Sequential Backups

The original dashboard supported manual background backups for four isolated WordPress installations. That worked well, but it still required an administrator to open…
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Shocking!!! GitHub Still Doesn’t Fully Support IPv6 in Late 2026 (and A WARP Solution for an IPv6-Only VPS)

~ YIN Renlong

I’ll update this article when GitHub supports IPv6. Idk when…

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In 2026, an IPv6-only VPS could serve websites perfectly yet still fail at the humble task of pushing a backup to GitHub. The website was healthy; the route was not. This case study explains how I used Cloudflare WARP only for temporary IPv4 egress, deliberately kept native IPv6 and SSH outside the tunnel, and made every connection self-cleaning.

A Small Qualification Before the Shocking Part

The title is intentionally…
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Incremental Development of a WordPress GIF-WebP Mosaic Background Engine

~ YIN Renlong

Yin’s Background Studio (as shown in the background of this website) began as a small WordPress theme enhancement for selecting one repeating background and evolved into a validated composition engine supporting static, random, weighted, persistent, reduced-motion, mosaic and scattered-collage modes. The project demonstrates how to extend a mature theme safely while preserving existing media, limiting animation costs, avoiding layout shift and making every production change recoverable.

The original problem

The website originally displayed one selected background at a time. An…
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Engineering Dynamic Image/Video Backgrounds in a WordPress Theme

~ YIN Renlong

Yin’s Background Studio began as a refactoring task: replace a fragile, hard-coded random background selector with a native WordPress administration surface. The finished system stores multiple media-backed backgrounds in one option, supports static and random selection modes, handles reduced-motion fallbacks, previews images and videos, and validates manual sizing on both the client and server while preserving rollback at every deployment.

Technical environment

The implementation was developed on a small, resource-constrained WordPress server. At the time of the work, the confirmed…
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Migrating Legacy WordPress Sites (PHP 7.1) to PHP 8.4 on an IPv6-Only VPS

~ YIN Renlong

Migrating one old WordPress site can be unpredictable. Migrating four of them simultaneously—from an obsolete operating system, an old PHP runtime, aging themes, and years of accumulated plugins—requires a process designed around containment rather than optimism.

The goal of this migration was not simply to copy files onto a new server. It was to establish a clean, verifiable baseline:

  • current WordPress core;
  • PHP 8.4;
  • Nginx and MariaDB on a modern Debian system;
  • Cloudflare-proxied public HTTPS;
  • the smallest practical active-plugin set;…
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A Hybrid Playwright and Google Analytics 4 API Pipeline for Weekly Analytics Reporting

~ YIN Renlong

Weekly reporting often begins as a small manual task:

  1. Open several analytics reports.
  2. Change each report to the same weekly date range.
  3. Wait for charts to load.
  4. download each report as PDF.
  5. Rename the files.
  6. export supporting CSV data.
  7. place everything in the correct folders.
  8. verify that no report is missing or incomplete.

None of these steps is particularly difficult. The problem is repetition, inconsistency, and silent failure. This article describes the architecture and engineering decisions behind a macOS automation…
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