Architectural Erosion from Fast Coding

1. Concept Overview & Systemic Problem

The speed of vibecoding creates a euphoric high: within three weeks, a startup releases a product that previously took a year to develop. Everyone is happy, and metrics are rising.

However, by the sixth month, the hangover begins — Architectural Erosion:

• Attempting to change a single field in the user profile suddenly breaks PDF report generation.
• It turns out there are three different methods for connecting to the database, four different form validation systems, and five different libraries for date handling in the project — each model in every chat used whatever came to mind first.
• The project becomes so fragile that even the most powerful model starts to get tangled in its own created contradictions.

2. Architectural Taxonomy & Mental Model

┌─────────────────────────────────────────────────────────────┐
│                 ARCHITECTURAL EROSION DYNAMICS              │
├─────────────────────────────────────────────────────────────┤
│ 1. DAY 1: CLEAN LAYERED ARCHITECTURE                        │
│    [ UI Layer ] ──► [ Business Service ] ──► [ Repository ] │
│    • Clear boundaries, deterministic interfaces               │
├─────────────────────────────────────────────────────────────┤
│                          │                                  │
│                          ▼ 100 AI Fast-Fixes without Specs  │
├─────────────────────────────────────────────────────────────┤
│ 2. DAY 180: ENTROPIC SPAGHETTI WEB                          │
│    • UI Component directly reads SQL                        │
│    • Business service mutates DOM elements bypassing React  │
│    • 14 circular dependencies                                 │
├─────────────────────────────────────────────────────────────┤
│                          │                                  │
│                          ▼ RESULT: TOTAL DEVELOPMENT FREEZE │
│ 3. The cost of adding any new feature increases tenfold      │
└─────────────────────────────────────────────────────────────┘

3. Technical Pipeline & Internal Mechanics

01. Implementing Dependency-Cruiser in CI

The team sets up an automatic rule: "Importing the DB module @/lib/db into components in the @/components/ui folder is prohibited." If an agent attempts to write a "quick fix," the build is immediately blocked by the architectural linter.

02. Weekly Architecture Sync Sessions

The tech lead spends two hours every Friday inspecting the global graph of the repository using Graphify, isolating modules that begin to grow too tightly intertwined.

4. Production Engineering Scenarios

01. Implementing Dependency-Cruiser in CI

The team sets up an automatic rule: "Importing the DB module @/lib/db into components in the @/components/ui folder is prohibited." If an agent attempts to write a "quick fix," the build is immediately blocked by the architectural linter.

02. Weekly Architecture Sync Sessions

The tech lead spends two hours every Friday inspecting the global graph of the repository using Graphify, isolating modules that begin to grow too tightly intertwined.

5. Pitfalls, Common Mistakes & Security

• The Illusion of "We'll Rewrite It Clean Later": Teams often think, "Let's just do it quickly with the agent now, and we'll refactor before the release." In 99% of cases, "later" never comes, and the project collapses under the weight of its own technical debt.
• Loss of Architectural Leadership: If there is no clear owner of the architecture (Lead Architect) within the team, the project becomes a lottery of random decisions made by various language models.