technical-knowledge

Personal technical knowledge base — Markdown articles grouped into nine top-level categories. Each category holds topic subdirectories; images, notebooks and code samples live next to the article that references them.

📅 最近更新 / Latest Articles — 最近新增或修改的文档，以及按加入时间倒序的完整目录（由 scripts/gen-latest.py 生成）。

Categories

Category	Contents
AI	LLM fundamentals, Transformer & attention internals, inference, agent harness, Claude Code, prompting, agents, model routing — 91 articles
Cloud	AWS services — EKS, networking, DynamoDB, Lambda, IAM/KMS — 13 articles
DevOps	CI/CD, Jenkins, Kubernetes, DNS, Linux, shell, observability — 59 articles
Languages	Java, Python, JavaScript and programming paradigms — 36 articles
Mobile	iOS and Android build, packaging, CloudKit and App Store review — 17 articles
Web	Front-end frameworks and markup — 3 articles
Data & ML	Data preparation, notebooks, deep learning, local LLMs — 19 articles
Security	TLS/HTTPS, authentication, mobile app hardening — 10 articles
Tools	Docker, Git, VS Code and self-hosted services — 10 articles

Outside the categories, docs/ holds the backlog plus any plans and specs, and raw/ holds the unpolished study notes that the published article series are derived from.

Two kinds of content live outside the category tree:

• technical-repos.md — the pointer index into every companion "explanation repo" (a topic's article/series packed together with its runnable code in its own repository): micro-service-auth, O11y-Micro-Service, mcp-explain, blue-green-eks-fargate-alb.
• docs/ — the backlog plus any plans and specs; raw/ — unpolished study notes that the published article series are derived from.

AI

LLM fundamentals & inference, Claude Code, prompting, agents, model routing

Agents

• 把 Claude Code 接进 Agent 编排框架：ACP 集成的四个反直觉发现
• AI Agent 记忆的 6 个层级：从 CLAUDE.md 到「统一大脑」
• Build an AI Assistant with LangGraph, Vercel, and Next.js: Use Gmail as a Tool Securely

Claude Code

• Claude Code Deep Dive (pdf)
• Claude Code 安装指南
• claude skill
• Using Claude Code Efficiently
• iOS UI design for AI-powered dictionary app
• One Layer vs Two Layers: Claude Skill Structure
• skill
• How Playwright Works with Claude Code
• chrome-devtools-mcp 与 Playwright：调试者的眼睛 vs. 测试者的手 · chrome-devtools-mcp vs. Playwright: Debugger's Eyes vs. Tester's Hands
• Claude Skills Marketplace

Concepts

• AI 核心概念梳理：LLM / Prompt / Agent / RAG / MCP / Skill / Context / Harness
• LLM 量化版本 是什么版本
• 为什么大量公司上了 RAG，却很少真正做成？ · Why So Many Companies Adopt RAG, and So Few Actually Succeed

DeepSeek Harness — 十二篇中文系列，见 series index

• 01 · 为什么需要 harness：模型再强，也不会自己去读文件

• 02 · DeepSeek Harness 是什么：定义、边界与生态位置

• 03 · 概念地图：八个概念、八个角色、一个运行示例

• 04 · Cordis 内核：为什么「一切皆插件」不是口号

• 05 · 组装层：Profile、Bundle、Patch 与 Agent Preset

• 06 · 会话日志：唯一真相源，以及「模型可见即已记录」

• 07 · Agent Loop：一个 turn 到底发生了什么

• 08 · 系统提示装配：模型看见的前缀是被「拼」出来的

• 09 · LLM 接缝：把厂商协议关进一个可替换的盒子

• 10 · 工具注册表与执行管线：一次工具调用要过五道关

• 11 · 能力接缝：文件、命令、沙箱、审批、子代理

• 12 · 完整重演：一句话请求的完整旅程 + 动手练习 LLM Fundamentals — 十三篇中文系列，见 series index

• 01 · 为什么会有 LLM：一个任务一个模型的时代是怎么结束的

• 02 · LLM 到底是什么：定义、边界与生态位置

• 03 · 七个核心概念：一次摊开整张地图

• 04 · Transformer 内部构造：那几十亿个参数到底排成什么样

• 05 · Tokenizer：模型眼里的世界不是文字

• 06 · 训练管线：数据如何变成权重

• 07 · 后训练细拆：SFT、RLHF、DPO、RLVR 四代工具

• 08 · 推理引擎：权重如何被读取

• 09 · 参数规模与 Scaling Law：7B、70B、670B 为什么如此重要

• 10 · 上下文窗口：128K 到底意味着什么

• 11 · 幻觉的机制：为什么它编得如此流畅

• 12 · 开源 vs 闭源：同一份权重，两种交付

• 13 · 完整重演：带着全部深度重跑运行示例

LLM Inference — 中英双语文章系列，见 series index

• 一次 LLM 推理的完整旅程 · The Full Journey of an LLM Inference Request
• KV Cache 完全解析 · KV Cache Explained
• Chat 阶段 vs Agentic 阶段 · Chat vs. Agentic
• GPU 负责想，CPU 负责做 · GPUs Think, CPUs Do
• 会续写 ≠ 会帮忙：后训练 · Completing Text ≠ Being Helpful
• FP16 与 INT4 量化 · FP16 and INT4 Quantization

Model Routing

• Hidden Reasoning Tokens Truncate Structured JSON Output
• How to user deeprouter api
• OpenRouter Auto Router vs Model Fallbacks
• OpenRouter

Multimodal — 十篇中文系列，见 series index

• 01 · 为什么需要多模态：纯文本 LLM 撞上的四堵墙
• 02 · 多模态 LLM 是什么：定义、边界与生态位置
• 03 · 概念地图：七个概念、五个角色、一个运行示例
• 04 · 视觉编码器：像素如何变成语义
• 05 · 对齐投影器：最小也最关键的模块
• 06 · LLM 主干与融合策略：前缀拼接 vs 交叉注意力
• 07 · 训练管线：三阶段如何把三个模块焊在一起
• 08 · 模态解码器与 Any-to-Any
• 09 · 完整重演：一张截图的完整旅程 + 动手练习

OpenClaw

• openclaw token
• setup

Prompting

• Cognitive Mental Model — Learning New Systems in Software Engineering
• 如何用 AI 整理自己的思路
• ChatGPT is the world's best money maker.
• Prompts for AI
• ChatGPT is FREE education.

Resources

• RSS

Superpowers

• Superpowers — What It Does & How It Orchestrates Skills
• Why superpowers

Transformer & Attention — 十二篇中文系列，见 series index

• 01 · 为什么会有 Transformer：一句话必须一个词一个词地读，是怎么被打破的
• 02 · Transformer 到底是什么：定义、边界与生态位置
• 03 · 概念地图：八个概念、五个角色，一次摊开整张地图
• 04 · 运行示例：一句话的完整旅程（浅层追踪）
• 05 · 嵌入层与位置编码器：从整数到「带位置感的向量」
• 06 · 注意力核心：QKV 与缩放点积
• 07 · 多头与因果掩码：并行的多种关系，与不许偷看的铁律
• 08 · 工程变体：KV Cache、GQA/MQA/MLA 与 FlashAttention
• 09 · 前馈网络 FFN：那七成参数在干什么
• 10 · 残差与归一化：让 32 层不至于崩掉的那些胶水
• 11 · 输出头与采样器：从 4096 个数到一个汉字
• 12 · 完整重演：一句话如何变成「猫」+ 动手练习

General

• AI

Cloud

AWS services — EKS, networking, DynamoDB, Lambda, IAM/KMS

AWS

• 备战 AWS Certification 考试
• KMS Encrypt Decrypt

AWS › CIDR Allocation

• Allocate CIDR dynamically via `cidrsubnet

AWS › DynamoDB

• DynamoDB Stream

AWS › EKS

• AWS EKS Add-ons Explained
• What is AWS EKS?
• ECS vs EKS

AWS › IPv4

• IPv4 + CIDR + Subnet

AWS › Lambda

• AWS Lambda and Connection-Bound Backends (CloudHSM, Relational Databases)
• how cloudwatch log structure
• sample

AWS › Networking

• A Practical Tour of AWS Networking: VPCs, Subnets, Gateways, and More
• 用 Internet Gateway 和公网 ALB 把私有子网里的服务暴露给公网用户 · Exposing a Service in Private Subnets Through an Internet Gateway and a Public ALB
• OSI 7-Layer Model in the Context of AWS

AWS › Step Functions

• Video Summary: AWS re:Invent 2024 – Building State Machines with AWS Step Functions Workflow Studio (API217)

General

• Cloud

DevOps

CI/CD, Jenkins, Kubernetes, DNS, Linux, shell, observability

CI/CD

• Continuous Integration & Continuous Delivery

DNS

• Using AWS Route 53 as Your Domain's Authoritative DNS Server
• How does DNS work ?
• DNS Record Types Explained
• How DNS Works: Key Components Explained

Jenkins

• Groovy- Difference between List, ArrayList and Object Array
• How to build a jenkins plugin?
• How to debug jenkins plugins on fly?
• How to release a Jenkins Plugin to Jenkins-CI artifactory?
• how to operation jenkins via api
• Jenkins 2 Pipeline definition (Configuration as Code)
• Jenkins Tips
• Make Jenkins pipeline in configuration as infrastructure way with job-dsl-plugin
• pipeline code snippet
• how make template pipeline

Jenkins › Docker

• Run jenkins master on docker

Kubernetes › CKDA

• Pod and Config
• Crash course for kubernetes
• Kubernetes Custom Resource Definitions (CRD)
• Cron
• Kubernetes Debugging Best Practices
• Kubernetes Deployment — Deep Dive
• Step 1: Add this env var
• Kubernetes Egress
• CKAD Exam Sample — Helm Topic
• how nodeport works
• Ingress
• Kubernetes Jobs & CronJobs: From Concepts to Examples
• Why Kubernetes Commands Use `sh -c
• 🧭 Kubernetes kubectl Cheat Sheet
• 🧪 CKAD Mock Exam — Intermediate Level
• Kubernetes Pod — Deep Dive
• Kubernetes Resource Management — Deep Dive
• Sealed Secret
• Kubernetes Security: Deep Dive
• Kubernetes Service Types
• Storage
• VI tips for K8S yaml edtion

Kubernetes › Experience

• ssl protocol conflict

Linux

• Understanding GID in Linux
• Understanding Linux Groups
• Linux Permission System
• Screen 会话管理

Networking

• Nginx 做反向代理：角色、实现，以及那些会咬人的默认值 · Nginx as a Reverse Proxy
• forward reverse proxy

Nexus

• Sonatype Nexus Repository Manager

Observability

• Instrumenting a Java Spring Boot Application on AWS EKS Fargate with Splunk Observability Cloud

Practices

• AgileAlliance
• Git Branching Strategies: Common Models, Trade-offs, and Choosing One for Correlated API Releases
• Multiple Mac mini share memory

Shell

• Zsh Subshell Variable Expansion
• Bash
• Difference Between bash and sh --- And Why Lightweight Images Include Only `sh
• find
• grep
• network tools
• Permission of file in Bash
• tree — 列目录并排除指定子目录
• TTY, PTY, and Non-TTY Shell Sessions
• zsh

General

• DevOps

Languages

Java, Python, JavaScript and programming paradigms

Java

• Spring Boot 启动生命周期：内嵌 Tomcat 到底是怎么跑起来的 · Spring Boot Startup Lifecycle: Hosting an Application With Embedded Tomcat
• 从 PV 操作、管程到现代 Java 并发 · From PV Operations and Monitors to Modern Java Concurrency
• CountDownLatch：Java 里最小的那个协调原语 · CountDownLatch in Java
• IntelliJ Tips
• How install multiple java version on M1 chip Mac
• trustStore keyStore

Java › Mono & Flux

• Reative flow

Java › Spring Boot

• Reactive Programming with Spring 5

Java › WebFlux

• How WebFlux improve I/O bound web service througout via async threading

JavaScript

• Bun: The All-in-One JavaScript Runtime and Toolkit
• Bun：把 JavaScript 工具链压缩成一个二进制
• Reactive Programming with RxJS: Async as a Stream You Can Operate On
• RxJS 响应式编程：把异步当成一条可以操作的流

Paradigms

• Light state cycle detection bug

Paradigms › Imperative Vs Declarative Program

• Declarative vs imperative programming

Python

• 算法题笔记：最长回文子串、Z 字形变换与合并有序链表
• How to debug Python with VS Code?
• jupyter notebook (notebook)
• postgresql bulk update with python
• Python 3 进阶复习手册
• requests` pip package
• Python threading.Semaphore 机制详解
• Python 切片 (Slice) 详解
• subprocess shell (notebook)
• uv：用一个工具替换整条 Python 工具链
• Why Use uv for Python

Python › argparse

• argparse

Python › Intro Programming

• class (notebook)
• decorator of python (notebook)
• dictionary (notebook)
• functional programming with python (notebook)
• python exception handling (notebook)

Python › NumPy

• numpy learning (notebook)

Python › Pythonschema

• pythonschema` could do json schema validation

General

• Languages

Mobile

iOS and Android build, packaging and architecture

Android

• Android App bundle vs Android APK
• android fundamental
• Android X Introduction
• Set up Google Play services
• gradle
• Difference Between Proguard and R8 in Android

iOS

• UIKit View Preview（AI Insight）
• CloudKit multi-device synchronization
• CloudKit Schema Deploy UI
• iOS certificate and provisioning profile planning
• What an ipa package contains, and the relationship among them?
• UIKit view preview in iOS development
• What do Workspace, Project , Target, Scheme, Build Settings, Configurations, Build Phases mean regarding iOS development?
• xcodebuild` Introduction
• 会意典应用被拒审核问题（App Store 审核被拒排查）

iOS › Best Way To Build Ios App

• iOS Mobile App Development Guide: Best Practices for Building iPhone Mobile Apps

iOS › Redux Ios

• redux for ios

General

• Mobile

Web

Front-end frameworks and markup

Frontend › AngularJS

• Angular development
• A hybrid mobile application base on angularjs

Frontend › HTML & CSS

• html element span

Frontend › Testing

• Playwright：把端到端测试从「玄学」变回工程 · Playwright: Reliable End-to-End Testing for Web Apps

General

• Web

Data & ML

Data preparation, notebooks, deep learning, local LLMs

Data Preparation

• 01 pandas basic (notebook)
• 02 matlab data visiualization (notebook)
• 03 pandas explore data (notebook)
• 04 deal missing data (notebook)
• 05 normalize data (notebook)
• 06 sample data (notebook)
• 07 build model (notebook)

Deep Learning

• What’s the difference between CNN and RNN?

LLaMA

• Exploring LLMs with MLX and the Neural Accelerators in the M5 GPU
• llama 2 model setup

Notebooks

• stock price predict with LSTM (notebook)

General

• Data & ML

Security

TLS/HTTPS, authentication, mobile app hardening

Auth

• 用 PKI 做用户与设备认证：把凭证从「共享秘密」换成「硬件私钥」 · Public Key Infrastructure for User and Device Authentication
• JWT
• microservice security
• 🏦 1. High-Level Flow Overview

Mobile Security

• Mobile App Certificate Pinning: Underlying Principle and a Swift Example
• Certificate pinning
• How Charles Proxy Works: From HTTP Proxy to HTTPS MITM Traffic Inspection
• Mobile API Token Security
• Runtime application self-protection

TLS

• how https works
• ssl

General

• Security

Tools

Docker, Git, VS Code and self-hosted services

Docker

• Why some container exit immediately
• docker
• pull ubuntu:trusty

Git

• Git Aliases Reference Guide
• Git, Finally Understood: A Snapshot Database and a Handful of Pointers
• 把 Git 想清楚：快照数据库 + 一堆指针
• git push hanging
• Git Tags in the Release Process: Lightweight, Annotated, and Signed
• Git 标签与发布流程：轻量标签、附注标签与签名标签

VS Code

• VS-Code

General

• Tools