Technical Analytical Writing

Communicate complex technical ideas clearly through structured analysis and evidence-based reasoning.

Document Types

Architecture Decision Record (ADR)

# ADR-{NNN}: {Decision Title}

**Status:** Proposed | Accepted | Deprecated | Superseded by ADR-{NNN}
**Date:** YYYY-MM-DD
**Deciders:** {names/roles}

## Context

What is the issue that motivates this decision? What forces are at play?

## Decision

What is the change being proposed or decided?

## Consequences

### Positive
- {benefit}

### Negative
- {tradeoff}

### Neutral
- {observation}

## Alternatives Considered

### {Alternative A}
- Pros: {list}
- Cons: {list}
- Why rejected: {reason}

System Analysis Document

# {System/Component} Analysis

## Executive Summary
{2-3 sentences: what, why, recommendation}

## Current State
{What exists today, with evidence}

## Problem Statement
{Specific, measurable issue being addressed}

## Analysis
{Evidence-based investigation}

## Recommendations
{Ordered by priority, with effort estimates}

## Appendix
{Raw data, detailed metrics, supplementary evidence}

Technical RFC

# RFC: {Title}

**Author:** {name}
**Status:** Draft | Review | Accepted | Rejected
**Created:** YYYY-MM-DD
**Review deadline:** YYYY-MM-DD

## Summary
{One paragraph: what this proposes}

## Motivation
{Why this is needed, with concrete examples}

## Detailed Design
{How it works, with diagrams and code examples}

## Drawbacks
{Honest assessment of downsides}

## Alternatives
{What else was considered and why this approach wins}

## Unresolved Questions
{Open items for discussion}

Writing Principles

Argument Structure

Every analytical section follows:

1. Claim — What you're asserting
2. Evidence — Data, metrics, code examples supporting the claim
3. Reasoning — Why the evidence supports the claim
4. Implication — What follows from this being true

Evidence Hierarchy

The Pyramid Principle

Lead with the conclusion, then support:

Bad:

We analyzed the database, then the cache layer, then the API, and found that response times are slow because the cache hit rate is only 23%.

Good:

Cache hit rate is 23%, causing slow response times. The database query layer generates cache keys inconsistently, leading to unnecessary misses. Standardizing key generation would bring hit rate to ~85%.

Structural Patterns

Problem-Solution-Evidence

## {Problem Name}

**Problem:** {specific, measurable issue}

**Solution:** {proposed change}

**Evidence:** {why this solution addresses the problem}

**Effort:** {T-shirt size + key dependencies}

Compare-Contrast Table

| Criterion | Option A | Option B | Option C |
|-----------|----------|----------|----------|
| Performance | ★★★ | ★★ | ★★★ |
| Complexity | Low | Medium | High |
| Team familiarity | High | Low | Medium |
| Maintenance cost | Low | High | Medium |
| **Recommendation** | **✓** | | |

Risk Matrix

| Risk | Likelihood | Impact | Mitigation |
|------|-----------|--------|------------|
| API rate limiting | High | Medium | Client-side rate limiter + cache |
| Data migration failure | Low | Critical | Rollback plan + dry-run first |
| Team bandwidth | Medium | High | Phased rollout |

Style Guidelines

Clarity

• Active voice: "The scheduler triggers the job" not "The job is triggered by the scheduler"
• Concrete nouns: "The API returns a 429 status" not "There are issues with the API"
• Specific numbers: "P99 latency is 230ms" not "Latency is high"

Conciseness

• Lead with the point, not the preamble
• One idea per paragraph
• Cut "In order to" → "To"
• Cut "It is important to note that" → (just state it)
• Cut "As mentioned previously" → (don't mention it)

Technical Accuracy

• Verify all metrics and measurements
• Include measurement methodology
• Distinguish between observations and interpretations
• Cite sources for external claims
• Date all data ("as of March 2026")

Diagrams

When to Use Diagrams

Mermaid for Inline Diagrams

```mermaid
graph LR
    A[Client] --> B[API Gateway]
    B --> C[Auth Service]
    B --> D[Skills Service]
    D --> E[(Database)]
```

Review Checklist

• Executive summary is self-contained (reader gets the point without reading further)
• Every claim has supporting evidence
• Alternatives are fairly presented (not strawmen)
• Risks and tradeoffs acknowledged honestly
• Audience-appropriate level of detail
• Diagrams have legends and labels
• All acronyms defined on first use
• Stranger test: a new team member can follow the argument

Anti-Patterns

• Burying the lead — Put conclusions first, evidence after
• Appeal to authority — "Google does it" is not an argument; explain why it works
• False precision — "This will improve performance by 47.3%" without measurement methodology
• Missing alternatives — Always compare at least 2-3 options
• Scope creep — Stay focused on the stated question; flag tangents for separate docs
• No expiration date — All analysis should include "valid as of" and conditions for revisiting