Stop Vibecoding: Why Specifications Save Your System
Garbage in, garbage out. Learn why defining clear specs before writing code is the only way to build reliable systems.
The Trap of ‘Vibecoding’
Have you ever started a project by just typing code, hoping the architecture would emerge as you go? It feels productive, but it often leads to a system that works by accident—until it doesn’t. In software, if you feed a system garbage assumptions, you get a garbage output.
What you see
On the surface, you see a developer rapidly pushing commits, features appearing in the UI, and a sense of momentum. It looks like progress, but without a plan, you are building on shifting sand.
What actually happens
When you skip specifications, you skip the ‘contract’ phase. A robust system relies on three layers:
- Domain Modeling: Defining the entities and their relationships before a single database table is created.
- Interface Contracts: Establishing how services talk to each other (e.g., API schemas, message formats).
- Constraint Definition: Setting the rules for what is valid data and what is not.
Without these, you end up with ‘spaghetti logic’ where every function has to guess what the previous one did.
Trace one example: The User Registration Flow
Imagine building a signup form.
Vibecoding approach: You write a function that takes a JSON blob and saves it to a database. If the user sends a missing field, the database crashes or saves null values.
Specification approach: You define a schema first. The system validates the input against that schema before it touches the database. If the data is ‘garbage,’ the system rejects it immediately with a clear error. The logic downstream can trust the data because the contract was enforced at the gate.
Why specs feel like magic
They feel slow at first, but they prevent ‘debugging debt.’ When you know exactly what a function receives and what it must return, you don’t need to write defensive code that checks for every possible error. You build with confidence.
Takeaway
Before you write a single line of code, write the spec. Define the inputs, the outputs, and the errors. Your future self will thank you.
