3. Logic (Business Logic Layer)
This is the brain of your app — where the real work happens.
Here’s where you define rules like "a user can’t buy something if they don’t have enough balance" or "admins can reset passwords." This layer is typically built using languages like JavaScript, Python, C#, or frameworks like Express.js and .NET.
Good business logic makes your app reliable and secure. It’s also where bugs often hide, so test it well.
This is the brain of your app — where the real work happens.
Here’s where you define rules like "a user can’t buy something if they don’t have enough balance" or "admins can reset passwords." This layer is typically built using languages like JavaScript, Python, C#, or frameworks like Express.js and .NET.
Good business logic makes your app reliable and secure. It’s also where bugs often hide, so test it well.