Tech Blog

Technical Blog Writing Skill

Write technical blog posts that explain system internals, architecture, and implementation details.

When to Use

• Explaining system internals or implementation details
• Source code analysis and walkthrough
• Comparing different implementations or approaches
• Doc-driven architecture/comparison posts (no source code in scope)

Document Structure

# [Topic] Deep Dive

Brief intro + why it matters.
> **Code Version**: Based on [project] `vX.Y.Z` tag (or commit id for external repos).

## 1. Introduction (problem + scope)
## 2. Background / Prerequisites
## 3-N. Core Content (by data flow, not code structure)
## N+1. Comparison / Trade-offs
## N+2. Code Index (files, functions, line numbers)
## References

Key guidelines:

• Chapter 1 = Introduction + Navigation only, no implementation details
• Organize content by data flow, not by code components
• Use > ⏭️ If reading first time, skip to §X, return here when needed.

Core Principles

1. Progressive Explanation

• Start with the problem, not the solution
• Build concepts layer by layer
• Explain "why" not just "what"

2. Concept-First (概念前置)

• Never use undefined terms: Define before use
• Add concept sections: Create §X.Y.1 to introduce concepts before implementation
• Use navigation hints: > ⏭️ If unfamiliar with X, see §Y first

3. Big Picture First (整体图景优先)

• Start with unified visual overview before details
• Use comparison diagrams/tables for 2+ approaches
• Show complete flow in one diagram

4. Balanced Comparison

• Analyze BOTH sides; don't cherry-pick
• Use comparison tables for similar concepts
• Identify what's truly different vs. equivalent

5. Design Decision Explanation

• What problem does it solve?
• What alternatives exist?
• What trade-offs?

6. Concrete Examples

• 1-2 practical examples per major section
• Show input → process → output
• Use real data for abstract concepts (e.g., inverted index with actual words)

7. Terminology Accuracy

• Verify terms via source code or official docs
• Define domain-specific terms when introducing
• Don't assume terms are interchangeable

Research Strategy

Source Code Exploration (MUST for project-specific details)

• Specific code logic, conditions, data structures
• Configuration parameters and defaults
• File paths and line numbers for citations
• Implementation variants (e.g., Wide vs Compact)

Knowledge/Memory (OK for standard protocols)

• Standard syntax (ES DSL, HTTP, SQL)
• Well-known algorithms (B+ tree, inverted index)
• Public documentation content

Doc-Driven Research (when no source code)

1. Extract claim list (defaults, limitations, "supports X")
2. Find authoritative sources (official docs → vendor blogs → community)
3. Cite at claim location: （来源：[Label]）
4. Use reference-style links: [Label]: https://...
5. Separate fact vs inference
6. Never fabricate numbers

💡 Don't search source code for info not in the project. Focus on project-specific implementation.

Writing Guidelines

Code Examples

• Include file path and line numbers
• Explain what it does, not just show it
• Replace large blocks with flow diagrams + key snippets
• Add practical query/command examples

Diagrams (Prefer Mermaid)

Use colors to distinguish components:

flowchart LR
    A[Client] --> B[Component A] --> C[Component B]
    style A fill:#e1f5fe,stroke:#01579b
    style B fill:#fff3e0,stroke:#e65100
    style C fill:#e8f5e9,stroke:#2e7d32

Color scheme:

• 🔵 Blue (#e1f5fe): Client/Entry points
• 🟠 Orange (#fff3e0): Processing components
• 🟢 Green (#e8f5e9): Data/Storage
• 🔴 Pink (#fce4ec): Distributed execution

Add step numbers for complex flows:

flowchart LR
    A -->|1. Request| B -->|2. Parse| C -->|3. Execute| D -->|4. Return| A

Tables

• Use for comparisons, performance data, component summaries

Callouts

• 💡 Key Point: Critical insights
• ⚠️ Gotcha: Common mistakes
• 📝 Terminology: Definitions
• ⏭️ Navigation: Cross-references

Hybrid Architecture Documentation

When documenting systems combining multiple technologies (e.g., ES + ClickHouse, Java + C++):

1. Clarify Component Responsibilities

• Don't assume: Each component's role may differ from standalone usage
• Verify: Which handles metadata? Query parsing? Distributed execution?
• Document boundaries: Where does one end and another begin?

Example (TSearch = ES + ClickHouse):

• ES: Metadata management, DSL parsing, routing table
• ClickHouse: Data storage, distributed query execution
• ⚠️ Common mistake: Assuming RPC handles distributed execution

2. Communication Mechanism Evolution

• Document history: "Initially Thrift RPC, now migrating to JNI"
• Current state: Which interfaces use which mechanism?
• Why the change: Performance? Simplicity?

3. Data Flow Verification

Before writing, trace actual flow:

1. Where does request enter?
2. Which component parses it?
3. How is it transformed?
4. Which component executes?
5. How are results returned?

Concept Consolidation (DRY)

When same concept appears in multiple sections:

1. Create ONE authoritative section
2. Other sections reference it: "See §3.1 for details"
3. Only add context-specific details elsewhere

When to consolidate: Same concept in 3+ sections, or updates require editing multiple places.

Data Integrity

NEVER Fabricate

• ❌ "Compression ratio is 16:1" (without test)
• ❌ "Query speed improved by 38%" (without benchmark)
• ✅ "LZ4 provides fast compression" (qualitative)
• ✅ "Based on [source], ratio is X:Y" (with citation)

Requires Citation

• Specific compression ratios
• Performance benchmarks
• Memory usage numbers
• Any quantitative comparison

Common Pitfalls

Large Document Operations

For documents >500 lines:

1. Create draft file: [topic]-DRAFT.md
2. Build new structure in draft
3. Review with user
4. Merge into original
5. Delete draft

Verification Checklist

Structure & Flow:

• Sections flow naturally with transitions
• Summary-detail pattern with overview diagrams
• Concepts introduced before use

Content Quality:

• Code examples include file paths and line numbers
• Each section has concrete examples
• No fabricated data; all numbers cited
• Terminology verified against source

Technical Accuracy:

• Code version/commit id specified
• Hybrid architecture responsibilities verified
• Communication mechanisms documented

Visual Clarity:

• Diagrams use colors and step numbers
• Comparison tables for similar concepts
• Practical query/command examples included

Output

• Location: docs/, ai_docs/, or project-specific folder
• Filename: [topic-name].md
• Language: Match user's preference