2nd/10_Wiki/Topics/Architecture/Architecture_Diagramming_Standards.md

---
id: wiki-2026-0508-architecture-diagramming-standar
title: Architecture Diagramming Standards
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [c4-model, arch-diagrams]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [architecture, diagrams, c4, documentation]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: mermaid
  framework: c4-plantuml
---

# Architecture Diagramming Standards

## 매 한 줄
> **"매 diagram 의 audience 의 결정한다"**. 매 C4 model (Simon Brown, 2018) 의 Context → Container → Component → Code 의 4-level zoom 의 default standard 의 됨. 매 2026 의 PlantUML + Mermaid + Structurizr DSL 의 most-used toolchain.

## 매 핵심

### 매 C4 Model levels
- **Level 1 — System Context**: 매 system + users + external systems. 매 non-technical audience.
- **Level 2 — Container**: 매 deployable units (web app, DB, queue). 매 technical overview.
- **Level 3 — Component**: 매 container 안의 logical components. 매 dev team.
- **Level 4 — Code**: 매 class diagram (rarely used — 매 IDE 의 generation 의 default).

### 매 supplementary diagrams
- **Sequence**: 매 request flow / interaction.
- **Deployment**: 매 infra topology (k8s, regions).
- **Dynamic**: 매 runtime view, message sequence.
- **State**: 매 entity lifecycle.

### 매 응용
1. ADR 의 embedded diagram — 매 context.
2. Onboarding 의 system overview.
3. Incident postmortem 의 affected component highlight.

## 💻 패턴

### C4 Context (Mermaid)
```mermaid
C4Context
  title System Context for Banking App
  Person(customer, "Customer", "Bank customer with accounts")
  System(banking, "Internet Banking", "Allows customers to view info")
  System_Ext(mainframe, "Mainframe", "Stores account, txn info")
  System_Ext(email, "Email System", "SMTP relay")
  Rel(customer, banking, "Uses", "HTTPS")
  Rel(banking, mainframe, "Reads/writes", "XML/HTTPS")
  Rel(banking, email, "Sends emails", "SMTP")
```

### C4 Container (PlantUML + C4-PlantUML)
```plantuml
@startuml
!include <C4/C4_Container>
Person(user, "User")
System_Boundary(c1, "Banking System") {
  Container(spa, "SPA", "React/TS", "UI")
  Container(api, "API", "Go/Gin", "JSON/HTTPS")
  ContainerDb(db, "Database", "Postgres 17", "Customers, accounts")
  Container(worker, "Worker", "Go", "Async jobs")
  ContainerQueue(mq, "Queue", "NATS JetStream")
}
Rel(user, spa, "Uses", "HTTPS")
Rel(spa, api, "Calls", "JSON/HTTPS")
Rel(api, db, "Reads/writes")
Rel(api, mq, "Publishes")
Rel(worker, mq, "Consumes")
@enduml
```

### Structurizr DSL (workspace-as-code)
```
workspace "Banking" {
  model {
    user = person "Customer"
    bank = softwareSystem "Banking" {
      spa = container "SPA" "React/TS"
      api = container "API" "Go/Gin"
      db = container "Database" "Postgres 17" "Database"
    }
    user -> spa "Uses"
    spa -> api "JSON/HTTPS"
    api -> db "SQL"
  }
  views {
    container bank "Containers" { include * autolayout lr }
    theme default
  }
}
```

### Sequence (Mermaid)
```mermaid
sequenceDiagram
  actor U as User
  participant S as SPA
  participant A as API
  participant D as DB
  U->>S: Click "Pay"
  S->>A: POST /payments
  A->>D: BEGIN; INSERT; COMMIT
  A-->>S: 201 Created
  S-->>U: Success toast
```

### Deployment (Mermaid)
```mermaid
flowchart LR
  subgraph k8s[Kubernetes / us-east-1]
    api[API Pods x3]
    worker[Worker Pods x2]
  end
  subgraph rds[RDS]
    pg[(Postgres 17 Multi-AZ)]
  end
  ALB --> api
  api --> pg
  worker --> pg
  worker --> SQS
```

### Diagrams as code (Python diagrams lib)
```python
from diagrams import Diagram, Cluster
from diagrams.aws.compute import ECS
from diagrams.aws.database import RDS
from diagrams.aws.network import ELB

with Diagram("Web", show=False, direction="LR"):
    lb = ELB("lb")
    with Cluster("Services"):
        svc = [ECS("svc1"), ECS("svc2")]
    db = RDS("primary")
    lb >> svc >> db
```

### Auto-generated from infra (Terraform → diagram)
```bash
# Inframap / Pluralith / Cloudcraft import
terraform graph | dot -Tpng > infra.png
inframap generate terraform.tfstate | dot -Tpng > clean.png
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| Quick sketch | Excalidraw / Whiteboard |
| Reusable, version-controlled | Mermaid (md-embedded) |
| Strict C4 + theming | Structurizr DSL |
| Cloud infra reality | Terraform → Inframap |
| Slide deck / exec | PlantUML + C4 theme + export |

**기본값**: Mermaid (C4 plugin) — 매 GitHub/Obsidian native rendering.

## 🔗 Graph
- 부모: [[Software Architecture]]
- 변형: [[ADR]] · [[RFC]]
- 응용: [[Onboarding]] · [[Postmortem]]
- Adjacent: [[Architecture Review (아키텍처 및 설계 리뷰)]] · [[Architecture_Refactor]]

## 🤖 LLM 활용
**언제**: text spec → Mermaid/PlantUML 의 generation, code → C4 inference.
**언제 X**: production diagram 의 unverified auto-generation — 매 hallucinated component 의 risk.

## ❌ 안티패턴
- **Box-and-line soup**: 매 layer/audience 의 mix 의 unreadable diagram.
- **Stale .png in repo**: 매 source-less binary — 매 update 의 X. Mermaid/DSL 의 사용.
- **Over-leveling**: 매 Level 4 (Code) 의 manually 의 maintain — 매 IDE 의 generate.
- **No legend**: 매 shape/color semantics 의 없는 diagram — 매 reader 의 confusion.

## 🧪 검증 / 중복
- Verified (Simon Brown, *Software Architecture for Developers*; c4model.com).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — C4 model + Mermaid/Structurizr/diagrams.py patterns |