Application Architecture
Create application architecture diagrams showing internal structure, layers, components, and dependencies within an application.
Application architecture diagrams show the internal structure of an application, including layers, components, and how they interact. These diagrams help developers understand the codebase and make informed design decisions.
What Application Architecture Shows
Application architecture diagrams typically include:
Layered Architecture
The most common application architecture pattern:
| Layer | Contents |
|---|---|
| Presentation Layer | UI, API controllers |
| Business Layer | Domain logic, services |
| Data Access Layer | Repositories, ORM |
| Infrastructure | Cross-cutting concerns, external services |
Creating Layer Diagrams
Tier Diagrams
Physical or logical tiers show how layers are deployed:
| Tier | Contents |
|---|---|
| Client Tier | Browser, mobile app, desktop |
| Web Tier | Web servers, API servers |
| Application Tier | Business logic servers |
| Data Tier | Databases, storage |
Creating Component Diagrams
Show the major components within an application:
Common Patterns
Visual Conventions
| Element | Representation |
|---|---|
| Components/modules/layers | Rectangles |
| Packages | Rectangles with tabs |
| Interfaces | Circles (lollipop notation) |
| Dependencies | Arrows (point toward dependency) |
| Optional components | Dashed boxes |
| Domains/layers | Colour coding |
Best Practices
Show Key Abstractions
Focus on important components, not every class.
Document Dependencies
Dependency direction matters for architecture.
Keep Diagrams Current
Update when architecture changes.
Link to Code
Use lineage linking to connect diagrams to packages.
Create Multiple Views
Overview diagram plus detailed component diagrams.
Version in Git
Architecture documentation belongs with code.