Layered Readability Principle¶
Core Idea: Same documentation serves everyone—from CEO to intern engineer.
The Challenge¶
Documentation readers have vastly different needs:
| Reader | Wants | Time Budget | Technical Level |
|---|---|---|---|
| CEO | Strategic overview | 5 minutes | Low |
| Investor | Market + moat | 30 minutes | Medium |
| Auditor | Security + compliance | 2 hours | High |
| CTO (external) | Architecture | 1 hour | Very High |
| New Engineer | How to contribute | 2 hours | High |
| Product Manager | Features + roadmap | 1 hour | Medium |
Problem: How do we serve all these needs without creating 6 different documentation sets?
Our Solution: Layered Architecture¶
Think of documentation like a pyramid:
┌─────────────────────────────────────────┐
│ Layer 1: Executive Summary (5-10 pages)│ ← CEO, Board
│ Vision, Market, Metrics │
└─────────────────────────────────────────┘
↓
┌─────────────────────────────────────────┐
│ Layer 2: Strategic (20-30 pages) │ ← Investors, Leadership
│ Business Model, Financials, Roadmap │
└─────────────────────────────────────────┘
↓
┌─────────────────────────────────────────┐
│ Layer 3: Architecture (50-100 pages) │ ← Auditors, CTOs
│ System Design, Security, AI/ML │
└─────────────────────────────────────────┘
↓
┌─────────────────────────────────────────┐
│ Layer 4: Implementation (100+ pages) │ ← Engineers, DevOps
│ API Docs, Service Specs, Runbooks │
└─────────────────────────────────────────┘
Each layer:
- ✅ Can stand alone
- ✅ Links deeper for those who need more
- ✅ Summarizes lower layers for those who don't
Layer 1: Executive Summary¶
Audience: CEO, Board Members, Busy Investors
Length: 5-10 pages
Purpose: "What is this product and why should I care?"
Content:
- Product vision (2 paragraphs)
- Market opportunity (1 chart)
- Key differentiators (bullet points)
- High-level architecture (1 diagram)
- Traction metrics (4-5 numbers)
- Team overview (names + titles)
- 12-month roadmap (timeline)
Tone: Business-focused, minimal jargon
Example Entry Point:
# MachineAvatars: AI-Powered Conversational Avatars
MachineAvatars enables businesses to deploy lifelike 3D AI chatbots
that understand context, speak naturally, and scale infinitely.
**Market:** $X billion conversational AI market growing at Y% CAGR
**Traction:** 50+ customers, $500K ARR, 95% retention
**Ask:** Series A to accelerate growth
Exit Points:
- Need technical details? → Layer 3 (Architecture)
- Want business model? → Layer 2 (Strategic)
- Just browsing? → Done, you got the gist
Layer 2: Strategic Documentation¶
Audience: Investors, Business Analysts, Product Leadership
Length: 20-30 pages
Purpose: "How does this business work and can it scale?"
Content:
- Business Model - Revenue streams, pricing
- Unit Economics - LTV, CAC, margins
- Market Analysis - TAM/SAM/SOM, competition
- Growth Strategy - Customer acquisition, expansion
- Financial Projections - 3-year model
- Product Roadmap - Quarterly features
- Team & Hiring - Org chart, key hires
- Risk Factors - What could go wrong?
Tone: Data-driven, strategic, explains "why"
Example Entry Point:
# Business Model
MachineAvatars uses a **SaaS subscription model** with three tiers:
| Tier | Price/mo | Target Customer | ARR/Customer |
| ------------ | -------- | --------------- | ------------ |
| Starter | $99 | SMBs | $1,188 |
| Professional | $499 | Mid-market | $5,988 |
| Enterprise | Custom | Large orgs | $50K+ |
**Current MRR:** $42K (85% Pro tier)
**Average LTV:** $15K
**Average CAC:** $3K
**LTV:CAC Ratio:** 5:1 ✅
Exit Points:
- Need technical architecture? → Layer 3
- Want API details? → Layer 4
- Enough for investment decision? → Done
Layer 3: Technical Architecture¶
Audience: Technical Auditors, External CTOs, Architects
Length: 50-100 pages
Purpose: "How is this actually built and is it sound?"
Content:
- System Architecture - Components, interactions
- AI/ML Architecture - Models, training, RAG
- Data Architecture - Databases, storage, flows
- Security Architecture - Auth, encryption, compliance
- Infrastructure - Cloud, scaling, DR
- Architecture Decision Records - Why we built it this way
- Integration Points - Third-party services
- Performance - Benchmarks, SLAs
Tone: Technical, diagram-heavy, evidence-based
Example Entry Point:
# System Architecture
MachineAvatars is built as a **microservices architecture**
with 20+ independent services:
```mermaid
graph TB
Frontend[Next.js Frontend]
Gateway[API Gateway :8000]
Auth[Auth Service :8001]
Chat3D[3D Chatbot :8011]
LLM[LLM Service :8016]
Frontend --> Gateway
Gateway --> Auth
Gateway --> Chat3D
Chat3D --> LLM
```
Why microservices? See ADR-004
Databases:
- MongoDB (Cosmos DB): User data, configurations
- Milvus: Vector embeddings (10M+ vectors)
- Azure Blob: Media storage
Traffic: 10K req/min peak, p95 latency < 200ms
**Exit Points:**
- Need service-level details? → Layer 4
- Want to see code? → GitHub repos
- Enough for architecture review? → Done
---
## Layer 4: Implementation Details
**Audience:** Engineers, DevOps, QA, New Hires
**Length:** 100+ pages (grows over time)
**Purpose:** "How do I work with/on this system?"
**Content:**
- **Service Documentation** - All 20+ services
- **API Reference** - Every endpoint, OpenAPI specs
- **Development Guides** - Setup, coding standards
- **Deployment Runbooks** - Step-by-step procedures
- **Troubleshooting** - Common issues, solutions
- **Testing** - Unit, integration, E2E strategies
- **Monitoring** - Dashboards, alerts, logs
**Tone:** Practical, code-heavy, copy-pasteable
**Example Entry Point:**
```markdown
# Auth Service
**Port:** 8001
**Purpose:** User authentication via JWT
**Owner:** Backend Team
## Quick Start
```bash
# Clone repo
git clone https://github.com/askgalore/machineagents-be
# Navigate to service
cd auth-service
# Install dependencies
pip install -r requirements.txt
# Run locally
uvicorn main:app --port 8001
API Endpoints¶
POST /login¶
Authenticates user and returns JWT.
Request:
Response (200):
Errors:
401- Invalid credentials429- Rate limit exceeded
Rate Limit: 5 req/min per IP
**Exit Points:**
- Need architecture context? → Layer 3
- Want business justification? → Layer 2
- Just need to use this API? → Done
---
## How Layers Connect
### Visual Navigation
Each layer has clear **entry points** and **exit points**:
**Homepage (`index.md`):**
```markdown
## Documentation Sections
### For Executives & Investors
- [Executive Summary](1-executive-summary/index.md) ← Layer 1
- [Business Documentation](2-business-documentation/index.md) ← Layer 2
### For Technical Auditors
- [System Architecture](3-product-architecture/index.md) ← Layer 3
- [AI/ML Architecture](4-ai-ml-architecture/index.md) ← Layer 3
### For Engineers & Developers
- [Technical Specification](6-technical-specification/index.md) ← Layer 4
- [API Documentation](6-technical-specification/api-documentation/index.md) ← Layer 4
Bidirectional Linking¶
Top-down (drill deeper):
# Executive Summary
...high-level overview...
**Want technical details?**
→ [System Architecture](../3-product-architecture/index.md)
→ [AI/ML Deep Dive](../4-ai-ml-architecture/index.md)
Bottom-up (context):
# Auth Service (Layer 4)
...detailed implementation...
**Why was JWT chosen over sessions?**
→ See [ADR-008: Authentication Strategy](../../13-architecture-decision-records/adr-008-auth.md) (Layer 3)
**Business impact:**
→ Enables stateless horizontal scaling ([Business Model](../../2-business-documentation/scalability.md)) (Layer 2)
Writing for Different Layers¶
Layer 1: Executive (Inspire)¶
❌ Bad:
Our system utilizes RESTful microservices with event-driven
architecture, deployedon Kubernetes with horizontal pod autoscaling
backed by ETCD for service discovery.
✅ Good:
MachineAvatars scales automatically to handle millions of conversations
simultaneously, ensuring your customers never wait.
Layer 2: Strategic (Convince)¶
❌ Bad:
✅ Good:
Migration to Azure Cosmos DB reduced infrastructure costs by 40%
while improving uptime to 99.9%, directly impacting gross margin
from 62% to 71%.
Layer 3: Architecture (Explain)¶
❌ Bad:
✅ Good:
Milvus was selected for vector storage after benchmarking against
Pinecone, Weaviate, and Postgres pgvector. Key factors:
- Performance: 15ms p95 latency vs. 450ms for pgvector
- Cost: Self-hosted saves $2K/month at 1M vectors
- Control: Custom indexing strategies for our use case
See [ADR-003](../13-architecture-decision-records/adr-003-milvus.md)
for full analysis.
Layer 4: Implementation (Instruct)¶
❌ Bad:
✅ Good:
# Auth Service Quick Start
1. Set environment variables:
```bash
export JWT_SECRET="your-secret-key"
export TOKEN_EXPIRY=3600
- Run service:
- Test authentication:
Expected response: Status 200 with JWT token.
---
## Common Patterns
### Summarize-Then-Expand
**Pattern:**
```markdown
## System Architecture
MachineAvatars uses a microservices architecture with 20+ services,
MongoDB for data storage, and Milvus for vector embeddings.
**[Read full architecture →](system-overview.md)** (10 min read)
### Quick Facts
- Services: 20+
- Databases: 2 (MongoDB + Milvus)
- Peak Traffic: 10K req/min
- Latency: <200ms p95
Progressive Disclosure¶
## Payment Processing
We integrate with **Razorpay** for payments.
<details>
<summary>Technical Implementation</summary>
Razorpay integration uses their Checkout.js library on the frontend
and webhooks for server-side validation...
[Full payment architecture →](payment-architecture.md)
</details>
Audience Callouts¶
> **For Executives:** This section explains our AI technology
> at a high level. [Skip to business impact →](#business-impact)
> **For Engineers:** Implementation details are in
> [AI Service Specs](../7-technical-specification/llm-service.md)
Benefits¶
For Readers¶
✅ Find what they need quickly - Start at their level
✅ Don't get overwhelmed - Only dive deeper if interested
✅ Understand context - Can always go up a layer
For Writers¶
✅ DRY (Don't Repeat Yourself) - Write once, link from multiple places
✅ Clear scope - Know which layer you're writing for
✅ Easier maintenance - Update in one place
For Organization¶
✅ Serves all stakeholders - One docs repo, many audiences
✅ Professional appearance - Investors see polish
✅ Efficient - No duplicate documentation efforts
Anti-Patterns to Avoid¶
❌ Flat Documentation¶
Problem: Executives drown in technical details, engineers can't find anything.
❌ Duplicate Content¶
Problem: Maintenance nightmare, versions diverge.
Solution: Write once in appropriate layer, summary + link from others.
❌ Wrong Layer¶
Problem: Too technical for executives.
Fix: Move to Layer 3, summarize in Layer 1:
# Executive Summary
Our AI chatbots understand context by searching a knowledge base
of millions of documents in milliseconds.
**[Technical details →](3-product-architecture/rag-system.md)**
Success Metrics¶
| Metric | Target | Measure |
|---|---|---|
| CEO can understand product | 100% | Survey after reading Layer 1 |
| Engineers find answers fast | < 2 min | Time to find implementation details |
| Investors get full picture | 90%+ confidence | Post-due-diligence survey |
| No duplicate content | 0% | Automated similarity check |
Related Principles¶
- SSOT - Layers live in one place
- Versioned & Traceable - All layers version together
- Diagram-First - Diagrams work at all layers
Last Updated: 2025-12-26
Version: 1.0
Owner: Documentation Lead
"One documentation, infinite perspectives."