𝗔𝗜 𝗦𝗵𝗶𝗽𝘀 𝗬𝗼𝘂𝗿 𝗖𝗼𝗱𝗲 𝗜𝗻 𝗠𝗶𝗻𝘂𝘁𝗲𝘀. 𝗬𝗼𝘂𝗿 𝗧𝗲𝗮𝗺 𝗣𝗮𝘆𝘀 𝗳𝗼𝗿 𝗜𝘁 𝗳𝗼𝗿 𝗠𝗼𝗻𝘁𝗵𝘀.
AI writes code fast. That is the problem.
Speed is not the enemy. Unmaintainable speed is the enemy.
AI assistants ship working code in minutes. They do not ship code you can safely touch six months later. I see this pattern often. Teams ship fast and celebrate. Then the codebase becomes a place people fear. Every change breaks something else.
The cause is not complexity. The cause is coupling.
AI often jams everything into one function. It puts HTTP handling, raw SQL, and business rules in one file. This is tight coupling. It is a time bomb.
Think of a restaurant. If one waiter takes orders, cooks food, washes dishes, and manages inventory, they can handle five tables. They will fail at fifty tables. Mistakes grow. Training new staff becomes impossible.
A good kitchen uses layers. The waiter handles the table. The chef runs the kitchen. The pantry staff manages food. Each role has a clear boundary.
Your code needs these same boundaries.
The Controller The controller handles HTTP. It receives a request. It calls a service. It returns a response. It does not write SQL. It does not decide if an order is valid. It is a translator.
The Service This is where business logic lives. It handles pricing, credit checks, and workflows. It does not know about HTTP. It only knows how the business should behave.
The Repository The repository owns data access. It handles SQL queries and database logic. It does not care about business rules. It only knows how to store and retrieve data.
Loose coupling gives you three benefits:
- Testing. You can test logic without a database. Tests become fast.
- Refactoring. You can change your database without touching business rules.
- Onboarding. New engineers can read one layer to understand one concept.
AI tools optimize for the shortest path to a result. They follow tutorials and quick guides. This leads to messy code where every feature touches every file. The speed you gain today is debt you pay tomorrow.
Use AI to fill your layers, do not let it build the house.
Be explicit in your prompts:
- "Generate the service layer only. Assume a repository exists. No database queries."
- "Write a repository for the orders table. No business logic."
AI generates code. Architecture determines if that code survives. Define your layers first. Then let the AI fill them in.
What is your approach to structuring AI code? Share your thoughts below.