Latest writings
eFootball Player.bin 逆向手记：四次翻车教会我的事
从 FF 模式丢技能、编辑器搜不到球员、到 CSV 验证假警报——记录 eFootball 球员数据逆向中踩过的四个坑，以及它们背后的教训。
从被封到极速：一次爬虫对抗实录
目标：把 pesdb.net 上全部 37,650 张球员卡片的数据爬下来。从 TLS 指纹暴露、多线程崩溃、到发现一行 Cookie 省掉 97% 请求——完整记录一次反反爬实战。
AI 能客观吗？别闹了，它连「看到什么」都不是自己选的
很多人觉得 AI 是绝对理性的存在，比人类更中立、更没有情绪。但问题是——AI 学到的从来都不是真实世界，而是人类允许它看到的世界。
一个大小写问题，让我 debug 了一整个下午
用 Tauri + Rust 做的 LoL 桌面助手，技能数值全部显示为 0。排查了数据层、前端、后端，最后发现 bug 藏在一行 HashMap 的 key 里。
花一整天写解析器，然后发现腾讯已经帮我做完了
用 CDragon 自己写英雄联盟技能数值解析器，debug 到 93% 覆盖率。然后有人丢了一个腾讯 API 链接过来——0 解析，100% 覆盖。
差一点：一场英雄联盟教我的沟通课
因为怕被压力，我闭麦 20 分钟。没有沟通的团队，推到高地也会输。
Selected work
CS2 Tournament Database App
A database application designed around Counter-Strike 2 professional tournament data, featuring Oracle relational database, MongoDB NoSQL database, players, coaches, maps, matches, and data query modules.
League of Legends Desktop Assistant
A desktop assistant project built with Tauri 2, React, TypeScript, and Rust, focusing on League Client local read-only integration, data display, security boundaries, and frontend error handling.
FocusPomodoro AI
A focus analysis tool based on FastAPI, OpenCV, MediaPipe, and React that uses a camera to detect face states combined with Pomodoro workflow.
Sentinel Pomodoro
An emotion-aware anti-failing timer blueprint combining Flask, Socket.IO, OpenCV, MediaPipe, DeepFace, and React visualization.
External Sort in Java
Implementation of external merge sort in Java, including MakeRuns, MergeRuns, replacement selection, run boundary, and sort consistency.
String Math in Java
Implementing large integer addition, multiplication, and factorial using strings without relying on Java numeric operations.
Hey, I'm Jiahao Ren.
I'm a Computer Science student at the University of Waikato in New Zealand, focusing on databases, AI agents, desktop apps, cloud deployment, gaming analytics, and dev toolchains. I like turning course projects, technical experiments, and real-world lessons into blog posts.
I'm currently working on database applications, AI agent workflows, desktop tools, cloud deployment, and gaming analytics, turning course projects, experiments, and lessons learned into reusable notes and blog posts.
Skills & Tools
Get in touch
Feel free to reach out about projects, tech stacks, coursework, or dev workflows.
